56451659581 has 2 divisors, whose sum is σ = 56451659582. Its totient is φ = 56451659580.

The previous prime is 56451659483. The next prime is 56451659611. The reversal of 56451659581 is 18595615465.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 43894440100 + 12557219481 = 209510^2 + 112059^2 .

It is a cyclic number.

It is not a de Polignac number, because 56451659581 - 2¹⁵ = 56451626813 is a prime.

It is a super-2 number, since 2×56451659581² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (56451659081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28225829790 + 28225829791.

It is an arithmetic number, because the mean of its divisors is an integer number (28225829791).

Almost surely, 2^56451659581 is an apocalyptic number.

It is an amenable number.

56451659581 is a deficient number, since it is larger than the sum of its proper divisors (1).

56451659581 is an equidigital number, since it uses as much as digits as its factorization.

56451659581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6480000, while the sum is 55.

The spelling of 56451659581 in words is "fifty-six billion, four hundred fifty-one million, six hundred fifty-nine thousand, five hundred eighty-one".