21097909376 has 32 divisors (see below), whose sum is σ = 42563049600. Its totient is φ = 10415418624.

The previous prime is 21097909367. The next prime is 21097909411. The reversal of 21097909376 is 67390979012.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (32).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1033100 + ... + 1053323.

It is an arithmetic number, because the mean of its divisors is an integer number (1330095300).

Almost surely, 2^21097909376 is an apocalyptic number.

It is an amenable number.

21097909376 is an abundant number, since it is smaller than the sum of its proper divisors (21465140224).

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

21097909376 is an equidigital number, since it uses as much as digits as its factorization.

21097909376 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2086516 (or 2086504 counting only the distinct ones).

The product of its (nonzero) digits is 1285956, while the sum is 53.

The spelling of 21097909376 in words is "twenty-one billion, ninety-seven million, nine hundred nine thousand, three hundred seventy-six".