56491718557 has 2 divisors, whose sum is σ = 56491718558. Its totient is φ = 56491718556.

The previous prime is 56491718551. The next prime is 56491718587. The reversal of 56491718557 is 75581719465.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 55109440516 + 1382278041 = 234754^2 + 37179^2 .

It is a cyclic number.

It is not a de Polignac number, because 56491718557 - 2⁷ = 56491718429 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (56491718551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28245859278 + 28245859279.

It is an arithmetic number, because the mean of its divisors is an integer number (28245859279).

Almost surely, 2^56491718557 is an apocalyptic number.

It is an amenable number.

56491718557 is a deficient number, since it is larger than the sum of its proper divisors (1).

56491718557 is an equidigital number, since it uses as much as digits as its factorization.

56491718557 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10584000, while the sum is 58.

The spelling of 56491718557 in words is "fifty-six billion, four hundred ninety-one million, seven hundred eighteen thousand, five hundred fifty-seven".