656707643 has 2 divisors, whose sum is σ = 656707644. Its totient is φ = 656707642.

The previous prime is 656707633. The next prime is 656707657. The reversal of 656707643 is 346707656.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 656707643 - 2²² = 652513339 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 656707594 and 656707603.

It is not a weakly prime, because it can be changed into another prime (656707633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 328353821 + 328353822.

It is an arithmetic number, because the mean of its divisors is an integer number (328353822).

Almost surely, 2^656707643 is an apocalyptic number.

656707643 is a deficient number, since it is larger than the sum of its proper divisors (1).

656707643 is an equidigital number, since it uses as much as digits as its factorization.

656707643 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 635040, while the sum is 44.

The square root of 656707643 is about 25626.3076349286. The cubic root of 656707643 is about 869.2086179991.

The spelling of 656707643 in words is "six hundred fifty-six million, seven hundred seven thousand, six hundred forty-three".