57721639 has 8 divisors (see below), whose sum is σ = 61667840. Its totient is φ = 53866296.

The previous prime is 57721637. The next prime is 57721661. The reversal of 57721639 is 93612775.

57721639 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 57721639 - 2¹ = 57721637 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (57721637) 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 7 ways as a sum of consecutive naturals, for example, 21399 + ... + 23944.

It is an arithmetic number, because the mean of its divisors is an integer number (7708480).

Almost surely, 2^57721639 is an apocalyptic number.

57721639 is a deficient number, since it is larger than the sum of its proper divisors (3946201).

57721639 is a wasteful number, since it uses less digits than its factorization.

57721639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45429.

The product of its digits is 79380, while the sum is 40.

The square root of 57721639 is about 7597.4758308270. The cubic root of 57721639 is about 386.4674172446.

The spelling of 57721639 in words is "fifty-seven million, seven hundred twenty-one thousand, six hundred thirty-nine".