2021205715720 has 16 divisors (see below), whose sum is σ = 4547712860460. Its totient is φ = 808482286272.

The previous prime is 2021205715691. The next prime is 2021205715747. The reversal of 2021205715720 is 275175021202.

It can be written as a sum of positive squares in 2 ways, for example, as 2006511912196 + 14693803524 = 1416514^2 + 121218^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25265071407 + ... + 25265071486.

Almost surely, 2^{2021205715720} is an apocalyptic number.

2021205715720 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2021205715720 is an abundant number, since it is smaller than the sum of its proper divisors (2526507144740).

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

2021205715720 is a wasteful number, since it uses less digits than its factorization.

2021205715720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50530142904 (or 50530142900 counting only the distinct ones).

The product of its (nonzero) digits is 19600, while the sum is 34.

The spelling of 2021205715720 in words is "two trillion, twenty-one billion, two hundred five million, seven hundred fifteen thousand, seven hundred twenty".