218540904 has 32 divisors (see below), whose sum is σ = 548384640. Its totient is φ = 72576000.

The previous prime is 218540887. The next prime is 218540977. The reversal of 218540904 is 409045812.

It is a super-2 number, since 2×218540904² = 95520253442274432, which contains 22 as substring.

It is an unprimeable number.

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, 10297 + ... + 23304.

It is an arithmetic number, because the mean of its divisors is an integer number (17137020).

Almost surely, 2^218540904 is an apocalyptic number.

218540904 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

218540904 is an abundant number, since it is smaller than the sum of its proper divisors (329843736).

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

218540904 is a wasteful number, since it uses less digits than its factorization.

218540904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33881 (or 33877 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 33.

The square root of 218540904 is about 14783.1290327860. The cubic root of 218540904 is about 602.3435234677.

Subtracting from 218540904 its sum of digits (33), we obtain a triangular number (218540871 = T₂₀₉₀₆).

The spelling of 218540904 in words is "two hundred eighteen million, five hundred forty thousand, nine hundred four".