21115601633280 has 480 divisors, whose sum is σ = 84240528261120. Its totient is φ = 4387653550080.

The previous prime is 21115601633249. The next prime is 21115601633381. The reversal of 21115601633280 is 8233610651112.

It is a tau number, because it is divible by the number of its divisors (480).

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 31 ways as a sum of consecutive naturals, for example, 18365601 + ... + 19481439.

It is an arithmetic number, because the mean of its divisors is an integer number (175501100544).

Almost surely, 2^{21115601633280} is an apocalyptic number.

21115601633280 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 21115601633280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42120264130560).

21115601633280 is an abundant number, since it is smaller than the sum of its proper divisors (63124926627840).

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

21115601633280 is a wasteful number, since it uses less digits than its factorization.

21115601633280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1115893 (or 1115867 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 39.

The spelling of 21115601633280 in words is "twenty-one trillion, one hundred fifteen billion, six hundred one million, six hundred thirty-three thousand, two hundred eighty".