57021681 has 4 divisors (see below), whose sum is σ = 76028912. Its totient is φ = 38014452.

The previous prime is 57021667. The next prime is 57021683. The reversal of 57021681 is 18612075.

57021681 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, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 57021681 - 2⁹ = 57021169 is a prime.

It is a super-2 number, since 2×57021681² = 6502944208131522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (57021683) 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, 9503611 + ... + 9503616.

It is an arithmetic number, because the mean of its divisors is an integer number (19007228).

Almost surely, 2^57021681 is an apocalyptic number.

It is an amenable number.

57021681 is a deficient number, since it is larger than the sum of its proper divisors (19007231).

57021681 is a wasteful number, since it uses less digits than its factorization.

57021681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19007230.

The product of its (nonzero) digits is 3360, while the sum is 30.

The square root of 57021681 is about 7551.2701580595. The cubic root of 57021681 is about 384.8989018856.

The spelling of 57021681 in words is "fifty-seven million, twenty-one thousand, six hundred eighty-one".