57516721 has 4 divisors (see below), whose sum is σ = 60017472. Its totient is φ = 55015972.

The previous prime is 57516709. The next prime is 57516731. The reversal of 57516721 is 12761575.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 57516721 - 2¹¹ = 57514673 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (57516731) 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, 1250341 + ... + 1250386.

It is an arithmetic number, because the mean of its divisors is an integer number (15004368).

Almost surely, 2^57516721 is an apocalyptic number.

It is an amenable number.

57516721 is a deficient number, since it is larger than the sum of its proper divisors (2500751).

57516721 is a wasteful number, since it uses less digits than its factorization.

57516721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2500750.

The product of its digits is 14700, while the sum is 34.

The square root of 57516721 is about 7583.9779139974. The cubic root of 57516721 is about 386.0095414073.

The spelling of 57516721 in words is "fifty-seven million, five hundred sixteen thousand, seven hundred twenty-one".