218645808 has 20 divisors (see below), whose sum is σ = 564835128. Its totient is φ = 72881920.

The previous prime is 218645807. The next prime is 218645827. The reversal of 218645808 is 808546812.

It is a self number, because there is not a number n which added to its sum of digits gives 218645808.

It is not an unprimeable number, because it can be changed into a prime (218645803) 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, 2277513 + ... + 2277608.

Almost surely, 2^218645808 is an apocalyptic number.

It is an amenable number.

218645808 is an abundant number, since it is smaller than the sum of its proper divisors (346189320).

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

218645808 is a wasteful number, since it uses less digits than its factorization.

218645808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4555132 (or 4555126 counting only the distinct ones).

The product of its (nonzero) digits is 122880, while the sum is 42.

The square root of 218645808 is about 14786.6767057375. The cubic root of 218645808 is about 602.4398870255.

It can be divided in two parts, 218645 and 808, that added together give a triangular number (219453 = T₆₆₂).

The spelling of 218645808 in words is "two hundred eighteen million, six hundred forty-five thousand, eight hundred eight".