21402864724 has 12 divisors (see below), whose sum is σ = 37458443764. Its totient is φ = 10700452224.

The previous prime is 21402864719. The next prime is 21402864727. The reversal of 21402864724 is 42746820412.

It can be written as a sum of positive squares in 2 ways, for example, as 5735335824 + 15667528900 = 75732^2 + 125170^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21402864727) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 194757 + ... + 284140.

Almost surely, 2^21402864724 is an apocalyptic number.

It is an amenable number.

21402864724 is a deficient number, since it is larger than the sum of its proper divisors (16055579040).

21402864724 is a wasteful number, since it uses less digits than its factorization.

21402864724 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 490074 (or 490072 counting only the distinct ones).

The product of its (nonzero) digits is 172032, while the sum is 40.

The spelling of 21402864724 in words is "twenty-one billion, four hundred two million, eight hundred sixty-four thousand, seven hundred twenty-four".