218872644 has 12 divisors (see below), whose sum is σ = 510702864. Its totient is φ = 72957544.

The previous prime is 218872639. The next prime is 218872663. The reversal of 218872644 is 446278812.

218872644 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (12).

It is a junction number, because it is equal to n+sod(n) for n = 218872596 and 218872605.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9119682 + ... + 9119705.

It is an arithmetic number, because the mean of its divisors is an integer number (42558572).

Almost surely, 2^218872644 is an apocalyptic number.

It is an amenable number.

218872644 is an abundant number, since it is smaller than the sum of its proper divisors (291830220).

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

218872644 is a wasteful number, since it uses less digits than its factorization.

218872644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18239394 (or 18239392 counting only the distinct ones).

The product of its digits is 172032, while the sum is 42.

The square root of 218872644 is about 14794.3450007089. The cubic root of 218872644 is about 602.6481505251.

It can be divided in two parts, 21887 and 2644, that added together give a triangular number (24531 = T₂₂₁).

The spelling of 218872644 in words is "two hundred eighteen million, eight hundred seventy-two thousand, six hundred forty-four".