218404240 has 40 divisors (see below), whose sum is σ = 534519360. Its totient is φ = 82763136.

The previous prime is 218404237. The next prime is 218404243. The reversal of 218404240 is 42404812.

It is an interprime number because it is at equal distance from previous prime (218404237) and next prime (218404243).

It is a tau number, because it is divible by the number of its divisors (40).

It is not an unprimeable number, because it can be changed into a prime (218404243) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 70324 + ... + 73363.

It is an arithmetic number, because the mean of its divisors is an integer number (13362984).

Almost surely, 2^218404240 is an apocalyptic number.

218404240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

218404240 is an abundant number, since it is smaller than the sum of its proper divisors (316115120).

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

218404240 is a wasteful number, since it uses less digits than its factorization.

218404240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 143719 (or 143713 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 25.

The square root of 218404240 is about 14778.5060138026. The cubic root of 218404240 is about 602.2179392879.

The spelling of 218404240 in words is "two hundred eighteen million, four hundred four thousand, two hundred forty".