656939531 has 2 divisors, whose sum is σ = 656939532. Its totient is φ = 656939530.

The previous prime is 656939513. The next prime is 656939557. The reversal of 656939531 is 135939656.

Together with previous prime (656939513) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 656939531 - 2¹⁴ = 656923147 is a prime.

It is a super-2 number, since 2×656939531² = 863139094780999922, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (656939131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 328469765 + 328469766.

It is an arithmetic number, because the mean of its divisors is an integer number (328469766).

Almost surely, 2^656939531 is an apocalyptic number.

656939531 is a deficient number, since it is larger than the sum of its proper divisors (1).

656939531 is an equidigital number, since it uses as much as digits as its factorization.

656939531 is an evil number, because the sum of its binary digits is even.

The product of its digits is 656100, while the sum is 47.

The square root of 656939531 is about 25630.8316486219. The cubic root of 656939531 is about 869.3109138131.

The spelling of 656939531 in words is "six hundred fifty-six million, nine hundred thirty-nine thousand, five hundred thirty-one".