57561921 has 10 divisors (see below), whose sum is σ = 85987682. Its totient is φ = 38374560.

The previous prime is 57561913. The next prime is 57561929. The reversal of 57561921 is 12916575.

57561921 is a `hidden beast` number, since 5 + 7 + 561 + 92 + 1 = 666.

57561921 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (57561913) and next prime (57561929).

It can be written as a sum of positive squares in only one way, i.e., 57153600 + 408321 = 7560^2 + 639^2 .

It is not a de Polignac number, because 57561921 - 2³ = 57561913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (57561929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 355240 + ... + 355401.

Almost surely, 2^57561921 is an apocalyptic number.

It is an amenable number.

57561921 is a deficient number, since it is larger than the sum of its proper divisors (28425761).

57561921 is an equidigital number, since it uses as much as digits as its factorization.

57561921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 710653 (or 710644 counting only the distinct ones).

The product of its digits is 18900, while the sum is 36.

The square root of 57561921 is about 7586.9572952535. The cubic root of 57561921 is about 386.1106312151.

The spelling of 57561921 in words is "fifty-seven million, five hundred sixty-one thousand, nine hundred twenty-one".