21591000938 has 48 divisors (see below), whose sum is σ = 35530840800. Its totient is φ = 9834851520.

The previous prime is 21591000919. The next prime is 21591000967. The reversal of 21591000938 is 83900019512.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8502473 + ... + 8505011.

It is an arithmetic number, because the mean of its divisors is an integer number (740225850).

Almost surely, 2^21591000938 is an apocalyptic number.

21591000938 is a deficient number, since it is larger than the sum of its proper divisors (13939839862).

21591000938 is a wasteful number, since it uses less digits than its factorization.

21591000938 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2887 (or 2874 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 38.

The spelling of 21591000938 in words is "twenty-one billion, five hundred ninety-one million, nine hundred thirty-eight", and thus it is an aban number.