20972649187170 has 256 divisors, whose sum is σ = 60473236723200. Its totient is φ = 5154170434560.

The previous prime is 20972649187157. The next prime is 20972649187181. The reversal of 20972649187170 is 7178194627902.

20972649187170 is a `hidden beast` number, since 2 + 0 + 9 + 7 + 2 + 6 + 491 + 8 + 71 + 70 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 20972649187098 and 20972649187107.

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 127 ways as a sum of consecutive naturals, for example, 1833748692 + ... + 1833760128.

It is an arithmetic number, because the mean of its divisors is an integer number (236223580950).

Almost surely, 2^{20972649187170} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20972649187170, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30236618361600).

20972649187170 is an abundant number, since it is smaller than the sum of its proper divisors (39500587536030).

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

20972649187170 is a wasteful number, since it uses less digits than its factorization.

20972649187170 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21170 (or 21164 counting only the distinct ones).

The product of its (nonzero) digits is 21337344, while the sum is 63.

The spelling of 20972649187170 in words is "twenty trillion, nine hundred seventy-two billion, six hundred forty-nine million, one hundred eighty-seven thousand, one hundred seventy".