21165559392 has 48 divisors (see below), whose sum is σ = 55609615152. Its totient is φ = 7048834560.

The previous prime is 21165559369. The next prime is 21165559417. The reversal of 21165559392 is 29395556112.

It is a tau number, because it is divible by the number of its divisors (48).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8542 + ... + 205922.

It is an arithmetic number, because the mean of its divisors is an integer number (1158533649).

Almost surely, 2^21165559392 is an apocalyptic number.

It is an amenable number.

21165559392 is an abundant number, since it is smaller than the sum of its proper divisors (34444055760).

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

21165559392 is a wasteful number, since it uses less digits than its factorization.

21165559392 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 198511 (or 198503 counting only the distinct ones).

The product of its digits is 729000, while the sum is 48.

The spelling of 21165559392 in words is "twenty-one billion, one hundred sixty-five million, five hundred fifty-nine thousand, three hundred ninety-two".