18931297 has 36 divisors (see below), whose sum is σ = 25229568. Its totient is φ = 14137200.

The previous prime is 18931261. The next prime is 18931313. The reversal of 18931297 is 79213981.

It is not a de Polignac number, because 18931297 - 2⁷ = 18931169 is a prime.

It is a super-2 number, since 2×18931297² = 716788012204418, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (18931207) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 183748 + ... + 183850.

Almost surely, 2^18931297 is an apocalyptic number.

It is an amenable number.

18931297 is a deficient number, since it is larger than the sum of its proper divisors (6298271).

18931297 is a wasteful number, since it uses less digits than its factorization.

18931297 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 170 (or 152 counting only the distinct ones).

The product of its digits is 27216, while the sum is 40.

The square root of 18931297 is about 4351.0110319327. The cubic root of 18931297 is about 266.5181497659.

The spelling of 18931297 in words is "eighteen million, nine hundred thirty-one thousand, two hundred ninety-seven".