18221907684 has 24 divisors (see below), whose sum is σ = 42548925888. Its totient is φ = 6069520480.

The previous prime is 18221907659. The next prime is 18221907701. The reversal of 18221907684 is 48670912281.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 539007 + ... + 571814.

It is an arithmetic number, because the mean of its divisors is an integer number (1772871912).

Almost surely, 2^18221907684 is an apocalyptic number.

It is an amenable number.

18221907684 is an abundant number, since it is smaller than the sum of its proper divisors (24327018204).

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

18221907684 is a wasteful number, since it uses less digits than its factorization.

18221907684 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1112195 (or 1112193 counting only the distinct ones).

The product of its (nonzero) digits is 387072, while the sum is 48.

The spelling of 18221907684 in words is "eighteen billion, two hundred twenty-one million, nine hundred seven thousand, six hundred eighty-four".