57218409 has 12 divisors (see below), whose sum is σ = 82759300. Its totient is φ = 38094624.

The previous prime is 57218407. The next prime is 57218417. The reversal of 57218409 is 90481275.

57218409 is a `hidden beast` number, since 572 + 1 + 84 + 0 + 9 = 666.

57218409 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 45522009 + 11696400 = 6747^2 + 3420^2 .

It is not a de Polignac number, because 57218409 - 2¹ = 57218407 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (57218401) 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 11 ways as a sum of consecutive naturals, for example, 3627 + ... + 11295.

Almost surely, 2^57218409 is an apocalyptic number.

It is an amenable number.

57218409 is a deficient number, since it is larger than the sum of its proper divisors (25540891).

57218409 is a wasteful number, since it uses less digits than its factorization.

57218409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8504 (or 8501 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The square root of 57218409 is about 7564.2850951032. The cubic root of 57218409 is about 385.3410347521.

It can be divided in two parts, 572 and 18409, that added together give a palindrome (18981).

The spelling of 57218409 in words is "fifty-seven million, two hundred eighteen thousand, four hundred nine".