97991031 has 16 divisors (see below), whose sum is σ = 135871488. Its totient is φ = 62750400.

The previous prime is 97991021. The next prime is 97991057. The reversal of 97991031 is 13019979.

It is not a de Polignac number, because 97991031 - 2⁶ = 97990967 is a prime.

It is a super-2 number, since 2×97991031² = 19204484312885922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (97991021) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8896 + ... + 16586.

It is an arithmetic number, because the mean of its divisors is an integer number (8491968).

Almost surely, 2^97991031 is an apocalyptic number.

97991031 is a deficient number, since it is larger than the sum of its proper divisors (37880457).

97991031 is a wasteful number, since it uses less digits than its factorization.

97991031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7862.

The product of its (nonzero) digits is 15309, while the sum is 39.

The square root of 97991031 is about 9899.0419233378. The cubic root of 97991031 is about 461.0295638097.

The spelling of 97991031 in words is "ninety-seven million, nine hundred ninety-one thousand, thirty-one".