218628990 has 32 divisors (see below), whose sum is σ = 583011360. Its totient is φ = 58300992.

The previous prime is 218628947. The next prime is 218629001. The reversal of 218628990 is 99826812.

218628990 is a `hidden beast` number, since 2 + 18 + 628 + 9 + 9 + 0 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 404599 + ... + 405138.

It is an arithmetic number, because the mean of its divisors is an integer number (18219105).

Almost surely, 2^218628990 is an apocalyptic number.

218628990 is an abundant number, since it is smaller than the sum of its proper divisors (364382370).

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

218628990 is a wasteful number, since it uses less digits than its factorization.

218628990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 809753 (or 809747 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 45.

The square root of 218628990 is about 14786.1080071803. The cubic root of 218628990 is about 602.4244402871.

The spelling of 218628990 in words is "two hundred eighteen million, six hundred twenty-eight thousand, nine hundred ninety".