18856644 has 12 divisors (see below), whose sum is σ = 43998864. Its totient is φ = 6285544.

The previous prime is 18856639. The next prime is 18856667. The reversal of 18856644 is 44665881.

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 = 18856596 and 18856605.

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, 785682 + ... + 785705.

It is an arithmetic number, because the mean of its divisors is an integer number (3666572).

Almost surely, 2^18856644 is an apocalyptic number.

It is an amenable number.

18856644 is an abundant number, since it is smaller than the sum of its proper divisors (25142220).

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

18856644 is a wasteful number, since it uses less digits than its factorization.

18856644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1571394 (or 1571392 counting only the distinct ones).

The product of its digits is 184320, while the sum is 42.

The square root of 18856644 is about 4342.4237471716. The cubic root of 18856644 is about 266.1673622178.

The spelling of 18856644 in words is "eighteen million, eight hundred fifty-six thousand, six hundred forty-four".