57168721 has 3 divisors (see below), whose sum is σ = 57176283. Its totient is φ = 57161160.

The previous prime is 57168689. The next prime is 57168733. The reversal of 57168721 is 12786175.

The square root of 57168721 is 7561.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 13608721 + 43560000 = 3689^2 + 6600^2 .

It is not a de Polignac number, because 57168721 - 2⁵ = 57168689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (57168781) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 3781 + ... + 11341.

It is an arithmetic number, because the mean of its divisors is an integer number (19058761).

Almost surely, 2^57168721 is an apocalyptic number.

57168721 is the 7561-st square number.

57168721 is the 3781-st centered octagonal number.

It is an amenable number.

57168721 is a deficient number, since it is larger than the sum of its proper divisors (7562).

57168721 is an frugal number, since it uses more digits than its factorization.

57168721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15122 (or 7561 counting only the distinct ones).

The product of its digits is 23520, while the sum is 37.

The cubic root of 57168721 is about 385.2294601111.

The spelling of 57168721 in words is "fifty-seven million, one hundred sixty-eight thousand, seven hundred twenty-one".