21943251768 has 16 divisors (see below), whose sum is σ = 54858129480. Its totient is φ = 7314417248.

The previous prime is 21943251749. The next prime is 21943251793. The reversal of 21943251768 is 86715234912.

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, 457151055 + ... + 457151102.

Almost surely, 2^21943251768 is an apocalyptic number.

It is an amenable number.

21943251768 is an abundant number, since it is smaller than the sum of its proper divisors (32914877712).

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

21943251768 is a wasteful number, since it uses less digits than its factorization.

21943251768 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 914302166 (or 914302162 counting only the distinct ones).

The product of its digits is 725760, while the sum is 48.

The spelling of 21943251768 in words is "twenty-one billion, nine hundred forty-three million, two hundred fifty-one thousand, seven hundred sixty-eight".