21408320884 has 12 divisors (see below), whose sum is σ = 37603836900. Its totient is φ = 10664367488.

The previous prime is 21408320849. The next prime is 21408320909. The reversal of 21408320884 is 48802380412.

It can be written as a sum of positive squares in 2 ways, for example, as 2836627600 + 18571693284 = 53260^2 + 136278^2 .

It is a congruent number.

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, 9947029 + ... + 9949180.

It is an arithmetic number, because the mean of its divisors is an integer number (3133653075).

Almost surely, 2^21408320884 is an apocalyptic number.

It is an amenable number.

21408320884 is a deficient number, since it is larger than the sum of its proper divisors (16195516016).

21408320884 is a wasteful number, since it uses less digits than its factorization.

21408320884 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19896482 (or 19896480 counting only the distinct ones).

The product of its (nonzero) digits is 98304, while the sum is 40.

The spelling of 21408320884 in words is "twenty-one billion, four hundred eight million, three hundred twenty thousand, eight hundred eighty-four".