57121561 has 24 divisors (see below), whose sum is σ = 70014464. Its totient is φ = 45601920.

The previous prime is 57121553. The next prime is 57121573. The reversal of 57121561 is 16512175.

It is not a de Polignac number, because 57121561 - 2³ = 57121553 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (57121511) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 182341 + ... + 182653.

Almost surely, 2^57121561 is an apocalyptic number.

It is an amenable number.

57121561 is a deficient number, since it is larger than the sum of its proper divisors (12892903).

57121561 is a wasteful number, since it uses less digits than its factorization.

57121561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 409 (or 380 counting only the distinct ones).

The product of its digits is 2100, while the sum is 28.

The square root of 57121561 is about 7557.8807214721. The cubic root of 57121561 is about 385.1235022907.

The spelling of 57121561 in words is "fifty-seven million, one hundred twenty-one thousand, five hundred sixty-one".