20001971765972 has 36 divisors (see below), whose sum is σ = 40718804745780. Its totient is φ = 8572167281664.

The previous prime is 20001971765959. The next prime is 20001971765989. The reversal of 20001971765972 is 27956717910002.

It can be written as a sum of positive squares in 2 ways, for example, as 1690795693636 + 18311176072336 = 1300306^2 + 4279156^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 16370804 + ... + 17550132.

It is an arithmetic number, because the mean of its divisors is an integer number (1131077909605).

Almost surely, 2^{20001971765972} is an apocalyptic number.

It is an amenable number.

20001971765972 is an abundant number, since it is smaller than the sum of its proper divisors (20716832979808).

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

20001971765972 is a wasteful number, since it uses less digits than its factorization.

20001971765972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1265880 (or 1265871 counting only the distinct ones).

The product of its (nonzero) digits is 3333960, while the sum is 56.

The spelling of 20001971765972 in words is "twenty trillion, one billion, nine hundred seventy-one million, seven hundred sixty-five thousand, nine hundred seventy-two".