656891551 has 2 divisors, whose sum is σ = 656891552. Its totient is φ = 656891550.

The previous prime is 656891537. The next prime is 656891567. The reversal of 656891551 is 155198656.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 656891551 - 2²⁹ = 120020639 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (656891051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 328445775 + 328445776.

It is an arithmetic number, because the mean of its divisors is an integer number (328445776).

Almost surely, 2^656891551 is an apocalyptic number.

656891551 is a deficient number, since it is larger than the sum of its proper divisors (1).

656891551 is an equidigital number, since it uses as much as digits as its factorization.

656891551 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 324000, while the sum is 46.

The square root of 656891551 is about 25629.8956494169. The cubic root of 656891551 is about 869.2897497378.

The spelling of 656891551 in words is "six hundred fifty-six million, eight hundred ninety-one thousand, five hundred fifty-one".