21711418644 has 12 divisors (see below), whose sum is σ = 50659976864. Its totient is φ = 7237139544.

The previous prime is 21711418627. The next prime is 21711418679. The reversal of 21711418644 is 44681411712.

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

It is a congruent number.

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, 904642432 + ... + 904642455.

Almost surely, 2^21711418644 is an apocalyptic number.

It is an amenable number.

21711418644 is an abundant number, since it is smaller than the sum of its proper divisors (28948558220).

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

21711418644 is a wasteful number, since it uses less digits than its factorization.

21711418644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1809284894 (or 1809284892 counting only the distinct ones).

The product of its digits is 43008, while the sum is 39.

The spelling of 21711418644 in words is "twenty-one billion, seven hundred eleven million, four hundred eighteen thousand, six hundred forty-four".