2100200021221 has 2 divisors, whose sum is σ = 2100200021222. Its totient is φ = 2100200021220.

The previous prime is 2100200021209. The next prime is 2100200021251. The reversal of 2100200021221 is 1221200020012.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1111147892100 + 989052129121 = 1054110^2 + 994511^2 .

It is a cyclic number.

It is not a de Polignac number, because 2100200021221 - 2¹⁷ = 2100199890149 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2100200021251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1050100010610 + 1050100010611.

It is an arithmetic number, because the mean of its divisors is an integer number (1050100010611).

Almost surely, 2^{2100200021221} is an apocalyptic number.

It is an amenable number.

2100200021221 is a deficient number, since it is larger than the sum of its proper divisors (1).

2100200021221 is an equidigital number, since it uses as much as digits as its factorization.

2100200021221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 2100200021221 its reverse (1221200020012), we get a palindrome (3321400041233).

The spelling of 2100200021221 in words is "two trillion, one hundred billion, two hundred million, twenty-one thousand, two hundred twenty-one".