56897321581 has 2 divisors, whose sum is σ = 56897321582. Its totient is φ = 56897321580.

The previous prime is 56897321543. The next prime is 56897321633. The reversal of 56897321581 is 18512379865.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 56354012100 + 543309481 = 237390^2 + 23309^2 .

It is a cyclic number.

It is not a de Polignac number, because 56897321581 - 2⁹ = 56897321069 is a prime.

It is a super-2 number, since 2×56897321581² (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 (56897321381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28448660790 + 28448660791.

It is an arithmetic number, because the mean of its divisors is an integer number (28448660791).

Almost surely, 2^56897321581 is an apocalyptic number.

It is an amenable number.

56897321581 is a deficient number, since it is larger than the sum of its proper divisors (1).

56897321581 is an equidigital number, since it uses as much as digits as its factorization.

56897321581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3628800, while the sum is 55.

The spelling of 56897321581 in words is "fifty-six billion, eight hundred ninety-seven million, three hundred twenty-one thousand, five hundred eighty-one".