218638140 has 48 divisors (see below), whose sum is σ = 699643392. Its totient is φ = 49974336.

The previous prime is 218638127. The next prime is 218638141. The reversal of 218638140 is 41836812.

It is a super-3 number, since 3×218638140³ (a number of 26 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218638141) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 259864 + ... + 260703.

It is an arithmetic number, because the mean of its divisors is an integer number (14575904).

Almost surely, 2^218638140 is an apocalyptic number.

218638140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

218638140 is an abundant number, since it is smaller than the sum of its proper divisors (481005252).

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

218638140 is a wasteful number, since it uses less digits than its factorization.

218638140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 520586 (or 520584 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 33.

The square root of 218638140 is about 14786.4174159936. The cubic root of 218638140 is about 602.4328443369.

It can be divided in two parts, 21863 and 8140, that added together give a palindrome (30003).

The spelling of 218638140 in words is "two hundred eighteen million, six hundred thirty-eight thousand, one hundred forty".