21575759904 has 72 divisors (see below), whose sum is σ = 61422041772. Its totient is φ = 7184186880.

The previous prime is 21575759897. The next prime is 21575759917. The reversal of 21575759904 is 40995757512.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 19446860304 + 2128899600 = 139452^2 + 46140^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 231202 + ... + 310814.

Almost surely, 2^21575759904 is an apocalyptic number.

21575759904 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21575759904 is an abundant number, since it is smaller than the sum of its proper divisors (39846281868).

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

21575759904 is a wasteful number, since it uses less digits than its factorization.

21575759904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80570 (or 80559 counting only the distinct ones).

The product of its (nonzero) digits is 3969000, while the sum is 54.

The spelling of 21575759904 in words is "twenty-one billion, five hundred seventy-five million, seven hundred fifty-nine thousand, nine hundred four".