21718423884 has 12 divisors (see below), whose sum is σ = 50676322424. Its totient is φ = 7239474624.

The previous prime is 21718423871. The next prime is 21718423913. The reversal of 21718423884 is 48832481712.

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

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, 904934317 + ... + 904934340.

Almost surely, 2^21718423884 is an apocalyptic number.

It is an amenable number.

21718423884 is an abundant number, since it is smaller than the sum of its proper divisors (28957898540).

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

21718423884 is a wasteful number, since it uses less digits than its factorization.

21718423884 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1809868664 (or 1809868662 counting only the distinct ones).

The product of its digits is 688128, while the sum is 48.

The spelling of 21718423884 in words is "twenty-one billion, seven hundred eighteen million, four hundred twenty-three thousand, eight hundred eighty-four".