20997813288960 has 960 divisors, whose sum is σ = 79883953766400. Its totient is φ = 5217111244800.

The previous prime is 20997813288943. The next prime is 20997813288971. The reversal of 20997813288960 is 6988231879902.

20997813288960 is a `hidden beast` number, since 2 + 0 + 9 + 97 + 81 + 328 + 89 + 60 = 666.

It is a tau number, because it is divible by the number of its divisors (960).

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2563518465 + ... + 2563526655.

It is an arithmetic number, because the mean of its divisors is an integer number (83212451840).

Almost surely, 2^{20997813288960} is an apocalyptic number.

20997813288960 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 20997813288960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39941976883200).

20997813288960 is an abundant number, since it is smaller than the sum of its proper divisors (58886140477440).

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

20997813288960 is an equidigital number, since it uses as much as digits as its factorization.

20997813288960 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8313 (or 8281 counting only the distinct ones).

The product of its (nonzero) digits is 188116992, while the sum is 72.

The spelling of 20997813288960 in words is "twenty trillion, nine hundred ninety-seven billion, eight hundred thirteen million, two hundred eighty-eight thousand, nine hundred sixty".