21408864264 has 96 divisors (see below), whose sum is σ = 58555224000. Its totient is φ = 7066118016.

The previous prime is 21408864247. The next prime is 21408864299. The reversal of 21408864264 is 46246880412.

21408864264 is a `hidden beast` number, since 2 + 140 + 8 + 86 + 426 + 4 = 666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3231147 + ... + 3237765.

It is an arithmetic number, because the mean of its divisors is an integer number (609950250).

Almost surely, 2^21408864264 is an apocalyptic number.

21408864264 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21408864264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29277612000).

21408864264 is an abundant number, since it is smaller than the sum of its proper divisors (37146359736).

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

21408864264 is a wasteful number, since it uses less digits than its factorization.

21408864264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7067 (or 7060 counting only the distinct ones).

The product of its (nonzero) digits is 589824, while the sum is 45.

The spelling of 21408864264 in words is "twenty-one billion, four hundred eight million, eight hundred sixty-four thousand, two hundred sixty-four".