57720881 has 4 divisors (see below), whose sum is σ = 58511652. Its totient is φ = 56930112.

The previous prime is 57720847. The next prime is 57720889. The reversal of 57720881 is 18802775.

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 19280881 + 38440000 = 4391^2 + 6200^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-57720881 is a prime.

It is a super-2 number, since 2×57720881² = 6663400206832322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (57720889) 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, 395276 + ... + 395421.

It is an arithmetic number, because the mean of its divisors is an integer number (14627913).

Almost surely, 2^57720881 is an apocalyptic number.

It is an amenable number.

57720881 is a deficient number, since it is larger than the sum of its proper divisors (790771).

57720881 is an equidigital number, since it uses as much as digits as its factorization.

57720881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 790770.

The product of its (nonzero) digits is 31360, while the sum is 38.

The square root of 57720881 is about 7597.4259456740. The cubic root of 57720881 is about 386.4657255418.

The spelling of 57720881 in words is "fifty-seven million, seven hundred twenty thousand, eight hundred eighty-one".