57131209 has 4 divisors (see below), whose sum is σ = 57258900. Its totient is φ = 57003520.

The previous prime is 57131177. The next prime is 57131213. The reversal of 57131209 is 90213175.

57131209 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 16426809 + 40704400 = 4053^2 + 6380^2 .

It is a cyclic number.

It is not a de Polignac number, because 57131209 - 2⁵ = 57131177 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (57131279) 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 3 ways as a sum of consecutive naturals, for example, 63172 + ... + 64069.

It is an arithmetic number, because the mean of its divisors is an integer number (14314725).

Almost surely, 2^57131209 is an apocalyptic number.

It is an amenable number.

57131209 is a deficient number, since it is larger than the sum of its proper divisors (127691).

57131209 is a wasteful number, since it uses less digits than its factorization.

57131209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 127690.

The product of its (nonzero) digits is 1890, while the sum is 28.

The square root of 57131209 is about 7558.5189686869. The cubic root of 57131209 is about 385.1451839016.

The spelling of 57131209 in words is "fifty-seven million, one hundred thirty-one thousand, two hundred nine".