21664310784600 has 384 divisors, whose sum is σ = 77174310528000. Its totient is φ = 4972083264000.

The previous prime is 21664310784559. The next prime is 21664310784631. The reversal of 21664310784600 is 648701346612.

It is a self number, because there is not a number n which added to its sum of digits gives 21664310784600.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 182899395 + ... + 183017805.

It is an arithmetic number, because the mean of its divisors is an integer number (200974767000).

Almost surely, 2^{21664310784600} is an apocalyptic number.

21664310784600 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 21664310784600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38587155264000).

21664310784600 is an abundant number, since it is smaller than the sum of its proper divisors (55509999743400).

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

21664310784600 is a wasteful number, since it uses less digits than its factorization.

21664310784600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 119919 (or 119910 counting only the distinct ones).

The product of its (nonzero) digits is 1161216, while the sum is 48.

The spelling of 21664310784600 in words is "twenty-one trillion, six hundred sixty-four billion, three hundred ten million, seven hundred eighty-four thousand, six hundred".