21172980309600 has 288 divisors, whose sum is σ = 78771776783616. Its totient is φ = 4839028992000.

The previous prime is 21172980309599. The next prime is 21172980309617. The reversal of 21172980309600 is 690308927112.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 21172980309600.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 172995627 + ... + 173117973.

It is an arithmetic number, because the mean of its divisors is an integer number (273513113832).

Almost surely, 2^{21172980309600} is an apocalyptic number.

21172980309600 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 21172980309600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39385888391808).

21172980309600 is an abundant number, since it is smaller than the sum of its proper divisors (57598796474016).

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

21172980309600 is a wasteful number, since it uses less digits than its factorization.

21172980309600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132678 (or 132665 counting only the distinct ones).

The product of its (nonzero) digits is 326592, while the sum is 48.

The spelling of 21172980309600 in words is "twenty-one trillion, one hundred seventy-two billion, nine hundred eighty million, three hundred nine thousand, six hundred".