21513824392 has 8 divisors (see below), whose sum is σ = 40338420750. Its totient is φ = 10756912192.

The previous prime is 21513824363. The next prime is 21513824401. The reversal of 21513824392 is 29342831512.

It can be written as a sum of positive squares in only one way, i.e., 21098724516 + 415099876 = 145254^2 + 20374^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1344614017 + ... + 1344614032.

Almost surely, 2^21513824392 is an apocalyptic number.

It is an amenable number.

21513824392 is a deficient number, since it is larger than the sum of its proper divisors (18824596358).

21513824392 is a wasteful number, since it uses less digits than its factorization.

21513824392 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2689228055 (or 2689228051 counting only the distinct ones).

The product of its digits is 103680, while the sum is 40.

The spelling of 21513824392 in words is "twenty-one billion, five hundred thirteen million, eight hundred twenty-four thousand, three hundred ninety-two".