218404140 has 48 divisors (see below), whose sum is σ = 616962528. Its totient is φ = 57723904.

The previous prime is 218404139. The next prime is 218404157. The reversal of 218404140 is 41404812.

It is a self number, because there is not a number n which added to its sum of digits gives 218404140.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9327 + ... + 22886.

It is an arithmetic number, because the mean of its divisors is an integer number (12853386).

Almost surely, 2^218404140 is an apocalyptic number.

218404140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

218404140 is an abundant number, since it is smaller than the sum of its proper divisors (398558388).

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

218404140 is a wasteful number, since it uses less digits than its factorization.

218404140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32338 (or 32336 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 24.

The square root of 218404140 is about 14778.5026305103. The cubic root of 218404140 is about 602.2178473761.

Adding to 218404140 its reverse (41404812), we get a palindrome (259808952).

The spelling of 218404140 in words is "two hundred eighteen million, four hundred four thousand, one hundred forty".