31864489 has 2 divisors, whose sum is σ = 31864490. Its totient is φ = 31864488.

The previous prime is 31864471. The next prime is 31864513. The reversal of 31864489 is 98446813.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 30691600 + 1172889 = 5540^2 + 1083^2 .

It is a cyclic number.

It is not a de Polignac number, because 31864489 - 2⁵ = 31864457 is a prime.

It is a super-2 number, since 2×31864489² = 2030691318462242, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (31864429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15932244 + 15932245.

It is an arithmetic number, because the mean of its divisors is an integer number (15932245).

Almost surely, 2^31864489 is an apocalyptic number.

It is an amenable number.

31864489 is a deficient number, since it is larger than the sum of its proper divisors (1).

31864489 is an equidigital number, since it uses as much as digits as its factorization.

31864489 is an evil number, because the sum of its binary digits is even.

The product of its digits is 165888, while the sum is 43.

The square root of 31864489 is about 5644.8639487591. The cubic root of 31864489 is about 317.0314298432.

The spelling of 31864489 in words is "thirty-one million, eight hundred sixty-four thousand, four hundred eighty-nine".