20897021537280 has 1408 divisors, whose sum is σ = 86959861401600. Its totient is φ = 4660428275712.

The previous prime is 20897021537267. The next prime is 20897021537291. The reversal of 20897021537280 is 8273512079802.

20897021537280 is a `hidden beast` number, since 2 + 0 + 8 + 9 + 7 + 0 + 21 + 537 + 2 + 80 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 7066965562 + ... + 7066968518.

It is an arithmetic number, because the mean of its divisors is an integer number (61761265200).

Almost surely, 2^{20897021537280} is an apocalyptic number.

20897021537280 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 20897021537280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43479930700800).

20897021537280 is an abundant number, since it is smaller than the sum of its proper divisors (66062839864320).

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

20897021537280 is a wasteful number, since it uses less digits than its factorization.

20897021537280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3174 (or 3150 counting only the distinct ones).

The product of its (nonzero) digits is 3386880, while the sum is 54.

The spelling of 20897021537280 in words is "twenty trillion, eight hundred ninety-seven billion, twenty-one million, five hundred thirty-seven thousand, two hundred eighty".