31386561 has 8 divisors (see below), whose sum is σ = 41893824. Its totient is φ = 20901840.

The previous prime is 31386529. The next prime is 31386577. The reversal of 31386561 is 16568313.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 31386561 - 2⁵ = 31386529 is a prime.

It is a super-2 number, since 2×31386561² = 1970232422813442, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (31386521) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2061 + ... + 8186.

It is an arithmetic number, because the mean of its divisors is an integer number (5236728).

Almost surely, 2^31386561 is an apocalyptic number.

It is an amenable number.

31386561 is a deficient number, since it is larger than the sum of its proper divisors (10507263).

31386561 is a wasteful number, since it uses less digits than its factorization.

31386561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11271.

The product of its digits is 12960, while the sum is 33.

The square root of 31386561 is about 5602.3710159182. The cubic root of 31386561 is about 315.4384119659.

The spelling of 31386561 in words is "thirty-one million, three hundred eighty-six thousand, five hundred sixty-one".