16931231 has 2 divisors, whose sum is σ = 16931232. Its totient is φ = 16931230.

The previous prime is 16931219. The next prime is 16931251. The reversal of 16931231 is 13213961.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16931231 is a prime.

It is a super-2 number, since 2×16931231² = 573333166350722, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 16931231.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16931251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8465615 + 8465616.

It is an arithmetic number, because the mean of its divisors is an integer number (8465616).

Almost surely, 2^16931231 is an apocalyptic number.

16931231 is a deficient number, since it is larger than the sum of its proper divisors (1).

16931231 is an equidigital number, since it uses as much as digits as its factorization.

16931231 is an evil number, because the sum of its binary digits is even.

The product of its digits is 972, while the sum is 26.

The square root of 16931231 is about 4114.7577085413. The cubic root of 16931231 is about 256.7809758635.

The spelling of 16931231 in words is "sixteen million, nine hundred thirty-one thousand, two hundred thirty-one".