57721664 has 224 divisors, whose sum is σ = 165908736. Its totient is φ = 19169280.

The previous prime is 57721663. The next prime is 57721673. The reversal of 57721664 is 46612775.

It is a tau number, because it is divible by the number of its divisors (224).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (57721661) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1089062 + ... + 1089114.

It is an arithmetic number, because the mean of its divisors is an integer number (740664).

Almost surely, 2^57721664 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 57721664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (82954368).

57721664 is an abundant number, since it is smaller than the sum of its proper divisors (108187072).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

57721664 is a wasteful number, since it uses less digits than its factorization.

57721664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113 (or 103 counting only the distinct ones).

The product of its digits is 70560, while the sum is 38.

The square root of 57721664 is about 7597.4774761101. The cubic root of 57721664 is about 386.4674730393.

Subtracting from 57721664 its reverse (46612775), we obtain a square (11108889 = 3333²).

It can be divided in two parts, 57721 and 664, that added together give a palindrome (58385).

The spelling of 57721664 in words is "fifty-seven million, seven hundred twenty-one thousand, six hundred sixty-four".