656866979 has 2 divisors, whose sum is σ = 656866980. Its totient is φ = 656866978.

The previous prime is 656866943. The next prime is 656866999. The reversal of 656866979 is 979668656.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 656866979 - 2²⁰ = 655818403 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (656866939) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 328433489 + 328433490.

It is an arithmetic number, because the mean of its divisors is an integer number (328433490).

Almost surely, 2^656866979 is an apocalyptic number.

656866979 is a deficient number, since it is larger than the sum of its proper divisors (1).

656866979 is an equidigital number, since it uses as much as digits as its factorization.

656866979 is an evil number, because the sum of its binary digits is even.

The product of its digits is 29393280, while the sum is 62.

The square root of 656866979 is about 25629.4162828575. The cubic root of 656866979 is about 869.2789105797.

The spelling of 656866979 in words is "six hundred fifty-six million, eight hundred sixty-six thousand, nine hundred seventy-nine".