Harshad (Niven) number checker
Harshad numbers divide evenly by their digit sum—18 works because 1+8=9 and 18/9=2. Try any integer to classify.
ClientNearby workflows on Toolcore
- Digital root calculator — Repeatedly sum digits until one digit remains—digital root for checksum tricks and divisibility games. when units or numeric output should be checked on a related calculator.
- Digit sum — Sum the decimal digits of a whole number—local arithmetic for puzzles and divisibility checks. when units or numeric output should be checked on a related calculator.
- Modulo calculator — Integer remainder and truncated quotient (a mod b)—BigInt math in your browser. when units or numeric output should be checked on a related calculator.
- Prime number checker — Test whether a whole number is prime—BigInt trial division in your browser, no upload. when units or numeric output should be checked on a related calculator.
Common use cases
- Explore digit-sum divisibility in recreational lists.
- Pair with digital root exercises.
Common mistakes to avoid
Zero
Not defined for n=0 in this checker.
FAQ
Other names?
Also called Niven numbers in some texts.
More tools
Related utilities you can open in another tab—mostly client-side.
Digital root calculator
ClientRepeatedly sum digits until one digit remains—digital root for checksum tricks and divisibility games.
Digit sum
ClientSum the decimal digits of a whole number—local arithmetic for puzzles and divisibility checks.
Modulo calculator
ClientInteger remainder and truncated quotient (a mod b)—BigInt math in your browser.
Prime number checker
ClientTest whether a whole number is prime—BigInt trial division in your browser, no upload.