21405858964 has 48 divisors (see below), whose sum is σ = 45115033600. Its totient is φ = 8681445216.

The previous prime is 21405858917. The next prime is 21405858979. The reversal of 21405858964 is 46985850412.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 467017 + ... + 510799.

Almost surely, 2^21405858964 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21405858964, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22557516800).

21405858964 is an abundant number, since it is smaller than the sum of its proper divisors (23709174636).

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

21405858964 is a wasteful number, since it uses less digits than its factorization.

21405858964 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44732 (or 44730 counting only the distinct ones).

The product of its (nonzero) digits is 2764800, while the sum is 52.

The spelling of 21405858964 in words is "twenty-one billion, four hundred five million, eight hundred fifty-eight thousand, nine hundred sixty-four".