656620969 has 2 divisors, whose sum is σ = 656620970. Its totient is φ = 656620968.

The previous prime is 656620957. The next prime is 656621011. The reversal of 656620969 is 969026656.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 618019600 + 38601369 = 24860^2 + 6213^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-656620969 is a prime.

It is a super-2 number, since 2×656620969² = 862302193860997922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (656620369) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 328310484 + 328310485.

It is an arithmetic number, because the mean of its divisors is an integer number (328310485).

Almost surely, 2^656620969 is an apocalyptic number.

It is an amenable number.

656620969 is a deficient number, since it is larger than the sum of its proper divisors (1).

656620969 is an equidigital number, since it uses as much as digits as its factorization.

656620969 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1049760, while the sum is 49.

The square root of 656620969 is about 25624.6164654225. The cubic root of 656620969 is about 869.1703761710.

The spelling of 656620969 in words is "six hundred fifty-six million, six hundred twenty thousand, nine hundred sixty-nine".