656449168691 has 16 divisors (see below), whose sum is σ = 678756421728. Its totient is φ = 634464230400.

The previous prime is 656449168679. The next prime is 656449168703. The reversal of 656449168691 is 196861944656.

It is an interprime number because it is at equal distance from previous prime (656449168679) and next prime (656449168703).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-656449168691 is a prime.

It is a super-2 number, since 2×656449168691² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (656449168601) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 35782181 + ... + 35800521.

It is an arithmetic number, because the mean of its divisors is an integer number (42422276358).

Almost surely, 2^656449168691 is an apocalyptic number.

656449168691 is a deficient number, since it is larger than the sum of its proper divisors (22307253037).

656449168691 is a wasteful number, since it uses less digits than its factorization.

656449168691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27062.

The product of its digits is 67184640, while the sum is 65.

The spelling of 656449168691 in words is "six hundred fifty-six billion, four hundred forty-nine million, one hundred sixty-eight thousand, six hundred ninety-one".