656764531 has 4 divisors (see below), whose sum is σ = 657559512. Its totient is φ = 655969552.

The previous prime is 656764529. The next prime is 656764561. The reversal of 656764531 is 135467656.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 656764531 - 2¹ = 656764529 is a prime.

It is a super-2 number, since 2×656764531² = 862679298359299922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (656764561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 396250 + ... + 397903.

It is an arithmetic number, because the mean of its divisors is an integer number (164389878).

Almost surely, 2^656764531 is an apocalyptic number.

656764531 is a deficient number, since it is larger than the sum of its proper divisors (794981).

656764531 is an equidigital number, since it uses as much as digits as its factorization.

656764531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 794980.

The product of its digits is 453600, while the sum is 43.

The square root of 656764531 is about 25627.4175640075. The cubic root of 656764531 is about 869.2337159823.

It can be divided in two parts, 65676 and 4531, that added together give a palindrome (70207).

The spelling of 656764531 in words is "six hundred fifty-six million, seven hundred sixty-four thousand, five hundred thirty-one".