57218720 has 48 divisors (see below), whose sum is σ = 145582920. Its totient is φ = 21126144.

The previous prime is 57218717. The next prime is 57218741. The reversal of 57218720 is 2781275.

It can be written as a sum of positive squares in 4 ways, for example, as 20106256 + 37112464 = 4484^2 + 6092^2 .

It is a Harshad number since it is a multiple of its sum of digits (32).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11675 + ... + 15834.

Almost surely, 2^57218720 is an apocalyptic number.

It is an amenable number.

57218720 is an abundant number, since it is smaller than the sum of its proper divisors (88364200).

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

57218720 is a wasteful number, since it uses less digits than its factorization.

57218720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27537 (or 27529 counting only the distinct ones).

The product of its (nonzero) digits is 7840, while the sum is 32.

The square root of 57218720 is about 7564.3056522063. The cubic root of 57218720 is about 385.3417329007.

Adding to 57218720 its reverse (2781275), we get a palindrome (59999995).

It can be divided in two parts, 5721 and 8720, that added together give a palindrome (14441).

The spelling of 57218720 in words is "fifty-seven million, two hundred eighteen thousand, seven hundred twenty".