21709491088 has 20 divisors (see below), whose sum is σ = 42071330700. Its totient is φ = 10852373504.

The previous prime is 21709491077. The next prime is 21709491127. The reversal of 21709491088 is 88019490712.

It can be written as a sum of positive squares in 2 ways, for example, as 12591532944 + 9117958144 = 112212^2 + 95488^2 .

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 3 ways as a sum of consecutive naturals, for example, 71545 + ... + 220312.

It is an arithmetic number, because the mean of its divisors is an integer number (2103566535).

Almost surely, 2^21709491088 is an apocalyptic number.

It is an amenable number.

21709491088 is a deficient number, since it is larger than the sum of its proper divisors (20361839612).

21709491088 is a wasteful number, since it uses less digits than its factorization.

21709491088 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 296514 (or 296508 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 49.

The spelling of 21709491088 in words is "twenty-one billion, seven hundred nine million, four hundred ninety-one thousand, eighty-eight".