31868689 has 2 divisors, whose sum is σ = 31868690. Its totient is φ = 31868688.

The previous prime is 31868677. The next prime is 31868723. The reversal of 31868689 is 98686813.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25150225 + 6718464 = 5015^2 + 2592^2 .

It is a cyclic number.

It is not a de Polignac number, because 31868689 - 2⁷ = 31868561 is a prime.

It is a super-2 number, since 2×31868689² = 2031226677157442, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (31868189) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15934344 + 15934345.

It is an arithmetic number, because the mean of its divisors is an integer number (15934345).

Almost surely, 2^31868689 is an apocalyptic number.

It is an amenable number.

31868689 is a deficient number, since it is larger than the sum of its proper divisors (1).

31868689 is an equidigital number, since it uses as much as digits as its factorization.

31868689 is an evil number, because the sum of its binary digits is even.

The product of its digits is 497664, while the sum is 49.

The square root of 31868689 is about 5645.2359560961. The cubic root of 31868689 is about 317.0453583422.

The spelling of 31868689 in words is "thirty-one million, eight hundred sixty-eight thousand, six hundred eighty-nine".