2100202020021 has 32 divisors (see below), whose sum is σ = 3213086450688. Its totient is φ = 1195327163520.

The previous prime is 2100202020017. The next prime is 2100202020073. The reversal of 2100202020021 is 1200202020012.

It is not a de Polignac number, because 2100202020021 - 2² = 2100202020017 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2100202019979 and 2100202020006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2100202020001) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 13773826 + ... + 13925468.

It is an arithmetic number, because the mean of its divisors is an integer number (100408951584).

Almost surely, 2^{2100202020021} is an apocalyptic number.

2100202020021 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

2100202020021 is a deficient number, since it is larger than the sum of its proper divisors (1112884430667).

2100202020021 is a wasteful number, since it uses less digits than its factorization.

2100202020021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 154281.

The product of its (nonzero) digits is 32, while the sum is 12.

Adding to 2100202020021 its reverse (1200202020012), we get a palindrome (3300404040033).

Subtracting from 2100202020021 its reverse (1200202020012), we obtain a palindrome (900000000009).

The spelling of 2100202020021 in words is "two trillion, one hundred billion, two hundred two million, twenty thousand, twenty-one".