21604334400 has 1008 divisors, whose sum is σ = 90740227968. Its totient is φ = 4816896000.

The previous prime is 21604334359. The next prime is 21604334431. The reversal of 21604334400 is 443340612.

21604334400 is a `hidden beast` number, since 21 + 604 + 3 + 34 + 4 + 0 + 0 = 666.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 191188744 + ... + 191188856.

Almost surely, 2^21604334400 is an apocalyptic number.

21604334400 is a gapful number since it is divisible by the number (20) 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 21604334400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45370113984).

21604334400 is an abundant number, since it is smaller than the sum of its proper divisors (69135893568).

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

21604334400 is a wasteful number, since it uses less digits than its factorization.

21604334400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 240 (or 222 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 27.

The spelling of 21604334400 in words is "twenty-one billion, six hundred four million, three hundred thirty-four thousand, four hundred".