97991231 has 8 divisors (see below), whose sum is σ = 105680064. Its totient is φ = 90324000.

The previous prime is 97991219. The next prime is 97991233. The reversal of 97991231 is 13219979.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 97991231 - 2²⁶ = 30882367 is a prime.

It is a super-2 number, since 2×97991231² = 19204562705790722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (97991233) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4745 + ... + 14781.

It is an arithmetic number, because the mean of its divisors is an integer number (13210008).

Almost surely, 2^97991231 is an apocalyptic number.

97991231 is a deficient number, since it is larger than the sum of its proper divisors (7688833).

97991231 is a wasteful number, since it uses less digits than its factorization.

97991231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10801.

The product of its digits is 30618, while the sum is 41.

The square root of 97991231 is about 9899.0520253204. The cubic root of 97991231 is about 461.0298774637.

The spelling of 97991231 in words is "ninety-seven million, nine hundred ninety-one thousand, two hundred thirty-one".