202100021221 has 18 divisors (see below), whose sum is σ = 243482292690. Its totient is φ = 167255155872.

The previous prime is 202100021177. The next prime is 202100021273. The reversal of 202100021221 is 122120001202.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 37678692100 + 164421329121 = 194110^2 + 405489^2 .

It is a de Polignac number, because none of the positive numbers 2^k-202100021221 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (202100021021) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 2410926 + ... + 2493343.

Almost surely, 2^202100021221 is an apocalyptic number.

It is an amenable number.

202100021221 is a deficient number, since it is larger than the sum of its proper divisors (41382271469).

202100021221 is an equidigital number, since it uses as much as digits as its factorization.

202100021221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4904341 (or 4904305 counting only the distinct ones).

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

Adding to 202100021221 its reverse (122120001202), we get a palindrome (324220022423).

The spelling of 202100021221 in words is "two hundred two billion, one hundred million, twenty-one thousand, two hundred twenty-one".