2021200021 has 2 divisors, whose sum is σ = 2021200022. Its totient is φ = 2021200020.

The previous prime is 2021200007. The next prime is 2021200063. The reversal of 2021200021 is 1200021202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1582925796 + 438274225 = 39786^2 + 20935^2 .

It is a cyclic number.

It is not a de Polignac number, because 2021200021 - 2²³ = 2012811413 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2021199980 and 2021200007.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2021200721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1010600010 + 1010600011.

It is an arithmetic number, because the mean of its divisors is an integer number (1010600011).

Almost surely, 2^2021200021 is an apocalyptic number.

It is an amenable number.

2021200021 is a deficient number, since it is larger than the sum of its proper divisors (1).

2021200021 is an equidigital number, since it uses as much as digits as its factorization.

2021200021 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 10.

The square root of 2021200021 is about 44957.7581847672. The cubic root of 2021200021 is about 1264.3571378816.

Adding to 2021200021 its reverse (1200021202), we get a palindrome (3221221223).

It can be divided in two parts, 202 and 1200021, that multiplied together give a palindrome (242404242).

The spelling of 2021200021 in words is "two billion, twenty-one million, two hundred thousand, twenty-one".