20972137489920 has 320 divisors, whose sum is σ = 74522045283840. Its totient is φ = 5590523142144.

The previous prime is 20972137489913. The next prime is 20972137490047. The reversal of 20972137489920 is 2998473127902.

20972137489920 is a `hidden beast` number, since 20 + 97 + 21 + 3 + 7 + 489 + 9 + 20 = 666.

It is a tau number, because it is divible by the number of its divisors (320).

It is a super-2 number, since 2×20972137489920² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 193689237 + ... + 193797483.

It is an arithmetic number, because the mean of its divisors is an integer number (232881391512).

Almost surely, 2^{20972137489920} is an apocalyptic number.

20972137489920 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 20972137489920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37261022641920).

20972137489920 is an abundant number, since it is smaller than the sum of its proper divisors (53549907793920).

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

20972137489920 is a wasteful number, since it uses less digits than its factorization.

20972137489920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111082 (or 111060 counting only the distinct ones).

The product of its (nonzero) digits is 27433728, while the sum is 63.

The spelling of 20972137489920 in words is "twenty trillion, nine hundred seventy-two billion, one hundred thirty-seven million, four hundred eighty-nine thousand, nine hundred twenty".