21915363856 has 40 divisors (see below), whose sum is σ = 42919405760. Its totient is φ = 10839712896.

The previous prime is 21915363809. The next prime is 21915363893. The reversal of 21915363856 is 65836351912.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1111621 + ... + 1131163.

It is an arithmetic number, because the mean of its divisors is an integer number (1072985144).

Almost surely, 2^21915363856 is an apocalyptic number.

It is an amenable number.

21915363856 is a deficient number, since it is larger than the sum of its proper divisors (21004041904).

21915363856 is a wasteful number, since it uses less digits than its factorization.

21915363856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20303 (or 20297 counting only the distinct ones).

The product of its digits is 1166400, while the sum is 49.

The spelling of 21915363856 in words is "twenty-one billion, nine hundred fifteen million, three hundred sixty-three thousand, eight hundred fifty-six".