Integer to English Words
A hard-tier problem at 34% community acceptance, tagged with Math, String, Recursion. Reported in interviews at Delhivery and 17 others.
Integer to English Words is a hard problem that appears across 18 companies, including Palantir, Block, and Roblox. You're given a number (0 to 2^31 - 1) and need to convert it to its English word representation. The acceptance rate sits at 34%, which means most candidates either time out on edge cases or get tripped up on the grouping logic. If this problem hits your live assessment and you blank on how to chunk the number or handle zero, StealthCoder surfaces a working solution in seconds, invisible to the proctor.
Companies that ask "Integer to English Words"
Integer to English Words is the kind of problem that decides whether you pass. StealthCoder reads the problem on screen and surfaces a working solution in under 2 seconds. Invisible to screen share. The proctor sees nothing. Made for the engineer who has done the work but might still blank with a webcam pointed at him.
Get StealthCoderThe trick is grouping digits into thousands, millions, and billions, then recursively converting each group. Candidates usually either try to brute-force a massive hardcoded mapping or fail to handle the grouping boundaries cleanly. The real pattern: break the number into chunks of three digits, map each chunk to words, and inject the scale word (thousand, million, billion). Edge cases kill this problem: leading zeros in chunks, the number zero itself, and skipping scale words when a chunk is zero. The topics are Math (place value), String (concatenation and formatting), and Recursion (building up from smaller subproblems). StealthCoder's value here is massive because the solution is methodical but brittle. One missed condition and your code fails 10 test cases.
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Integer to English Words recycles across companies for a reason. It's hard-tier, and most candidates blank under the timer. StealthCoder is the hedge: an AI overlay invisible during screen share. It reads the problem and surfaces a working solution in under 2 seconds. Made for the engineer who has done the work but might still blank with a webcam pointed at him. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Integer to English Words interview FAQ
Is this still actually asked at these companies?+
Yes. Palantir, Block, and Roblox have all reported this problem. It's a classic system-design adjacent problem because it teaches you to break large problems into modular pieces and handle boundary conditions rigorously. The 34% acceptance rate confirms it's live and hard.
What's the main trick I'm missing if I fail early attempts?+
You're not grouping correctly. Chunk the number into groups of three from right to left: ones, thousands, millions, billions. Map each chunk independently, then concatenate with the right scale word. Missing one scale word insertion or forgetting to skip zero-groups will fail multiple test cases.
Why is the acceptance rate so low?+
Edge cases. Zero, 1000, 1001, 1000000, numbers with internal zeros. Most candidates pass the happy path but fail on boundary cases. The String manipulation is tedious and error-prone. Recursion trips up some, but the real killer is incomplete edge-case handling.
How does Recursion fit this problem?+
You can solve it iteratively with a loop, but recursion elegantly handles the grouping. A recursive helper converts a number less than 1000 to words, and you call it on each chunk. Some solutions use recursion on the full number, dividing by 1000 each time. Both work if edges are tight.
Should I memorize all the word mappings before the OA?+
No. Write clean code that builds the mappings inline or as constants. The hard part isn't memorization, it's the logic for grouping, skipping zero-groups, and inserting scale words correctly. Practice on one full solution, get the structure right, then move on.
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