218545840 has 20 divisors (see below), whose sum is σ = 508119264. Its totient is φ = 87418304.

The previous prime is 218545813. The next prime is 218545843. The reversal of 218545840 is 48545812.

218545840 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (20).

It is a self number, because there is not a number n which added to its sum of digits gives 218545840.

It is not an unprimeable number, because it can be changed into a prime (218545843) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1365832 + ... + 1365991.

Almost surely, 2^218545840 is an apocalyptic number.

218545840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

218545840 is an abundant number, since it is smaller than the sum of its proper divisors (289573424).

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

218545840 is a wasteful number, since it uses less digits than its factorization.

218545840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2731836 (or 2731830 counting only the distinct ones).

The product of its (nonzero) digits is 51200, while the sum is 37.

The square root of 218545840 is about 14783.2959789081. The cubic root of 218545840 is about 602.3480583094.

The spelling of 218545840 in words is "two hundred eighteen million, five hundred forty-five thousand, eight hundred forty".