56731621 has 2 divisors, whose sum is σ = 56731622. Its totient is φ = 56731620.

The previous prime is 56731607. The next prime is 56731651. The reversal of 56731621 is 12613765.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 42185025 + 14546596 = 6495^2 + 3814^2 .

It is a cyclic number.

It is not a de Polignac number, because 56731621 - 2²³ = 48343013 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (56731651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28365810 + 28365811.

It is an arithmetic number, because the mean of its divisors is an integer number (28365811).

Almost surely, 2^56731621 is an apocalyptic number.

It is an amenable number.

56731621 is a deficient number, since it is larger than the sum of its proper divisors (1).

56731621 is an equidigital number, since it uses as much as digits as its factorization.

56731621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7560, while the sum is 31.

The square root of 56731621 is about 7532.0396308039. The cubic root of 56731621 is about 384.2451527918.

The spelling of 56731621 in words is "fifty-six million, seven hundred thirty-one thousand, six hundred twenty-one".