It is a happy number.
It is a sphenic number, since it is the product of 3 distinct primes.
It is a plaindrome in base 8, base 14 and base 16.
It is a nialpdrome in base 10.
It is a congruent number.
It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 9951.
29951 is an apocalyptic number.
9951 is a wasteful number, since it uses less digits than its factorization.
9951 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 141.
The square root of 9951 is about 99.7546991374. The cubic root of 9951 is about 21.5091001679.
The spelling of 9951 in words is "nine thousand, nine hundred fifty-one".