2101121200021 has 2 divisors, whose sum is σ = 2101121200022. Its totient is φ = 2101121200020.

The previous prime is 2101121200007. The next prime is 2101121200067. The reversal of 2101121200021 is 1200021211012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1249633336900 + 851487863121 = 1117870^2 + 922761^2 .

It is a cyclic number.

It is not a de Polignac number, because 2101121200021 - 2¹⁵ = 2101121167253 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2101121199974 and 2101121200010.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2101121206021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1050560600010 + 1050560600011.

It is an arithmetic number, because the mean of its divisors is an integer number (1050560600011).

Almost surely, 2^{2101121200021} is an apocalyptic number.

It is an amenable number.

2101121200021 is a deficient number, since it is larger than the sum of its proper divisors (1).

2101121200021 is an equidigital number, since it uses as much as digits as its factorization.

2101121200021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 2101121200021 its reverse (1200021211012), we get a palindrome (3301142411033).

The spelling of 2101121200021 in words is "two trillion, one hundred one billion, one hundred twenty-one million, two hundred thousand, twenty-one".