218781855 has 48 divisors (see below), whose sum is σ = 385987680. Its totient is φ = 114626304.

The previous prime is 218781833. The next prime is 218781869. The reversal of 218781855 is 558187812.

218781855 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 218781855 - 2²⁰ = 217733279 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 218781855.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1222156 + ... + 1222334.

It is an arithmetic number, because the mean of its divisors is an integer number (8041410).

Almost surely, 2^218781855 is an apocalyptic number.

218781855 is a deficient number, since it is larger than the sum of its proper divisors (167205825).

218781855 is a wasteful number, since it uses less digits than its factorization.

218781855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 520 (or 517 counting only the distinct ones).

The product of its digits is 179200, while the sum is 45.

The square root of 218781855 is about 14791.2763140981. The cubic root of 218781855 is about 602.5648122744.

The spelling of 218781855 in words is "two hundred eighteen million, seven hundred eighty-one thousand, eight hundred fifty-five".