2100200020021 has 16 divisors (see below), whose sum is σ = 2214205718400. Its totient is φ = 1986543629568.

The previous prime is 2100200020003. The next prime is 2100200020043. The reversal of 2100200020021 is 1200200020012.

It is not a de Polignac number, because 2100200020021 - 2⁵ = 2100200019989 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2100200020421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32461921 + ... + 32526553.

It is an arithmetic number, because the mean of its divisors is an integer number (138387857400).

Almost surely, 2^{2100200020021} is an apocalyptic number.

It is an amenable number.

2100200020021 is a deficient number, since it is larger than the sum of its proper divisors (114005698379).

2100200020021 is a wasteful number, since it uses less digits than its factorization.

2100200020021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67308.

The product of its (nonzero) digits is 16, while the sum is 10.

Adding to 2100200020021 its reverse (1200200020012), we get a palindrome (3300400040033).

Subtracting from 2100200020021 its reverse (1200200020012), we obtain a palindrome (900000000009).

The spelling of 2100200020021 in words is "two trillion, one hundred billion, two hundred million, twenty thousand, twenty-one".