57131381 has 4 divisors (see below), whose sum is σ = 57199212. Its totient is φ = 57063552.

The previous prime is 57131377. The next prime is 57131413. The reversal of 57131381 is 18313175.

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 2149156 + 54982225 = 1466^2 + 7415^2 .

It is a cyclic number.

It is not a de Polignac number, because 57131381 - 2² = 57131377 is a prime.

It is a super-2 number, since 2×57131381² = 6527989389934322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (57131341) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32636 + ... + 34341.

It is an arithmetic number, because the mean of its divisors is an integer number (14299803).

Almost surely, 2^57131381 is an apocalyptic number.

It is an amenable number.

57131381 is a deficient number, since it is larger than the sum of its proper divisors (67831).

57131381 is an equidigital number, since it uses as much as digits as its factorization.

57131381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67830.

The product of its digits is 2520, while the sum is 29.

The square root of 57131381 is about 7558.5303465687. The cubic root of 57131381 is about 385.1455704090.

The spelling of 57131381 in words is "fifty-seven million, one hundred thirty-one thousand, three hundred eighty-one".