202121001221 has 2 divisors, whose sum is σ = 202121001222. Its totient is φ = 202121001220.

The previous prime is 202121001217. The next prime is 202121001239. The reversal of 202121001221 is 122100121202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 201883070596 + 237930625 = 449314^2 + 15425^2 .

It is a cyclic number.

It is not a de Polignac number, because 202121001221 - 2² = 202121001217 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 202121001196 and 202121001205.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (202121001211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 101060500610 + 101060500611.

It is an arithmetic number, because the mean of its divisors is an integer number (101060500611).

Almost surely, 2^202121001221 is an apocalyptic number.

It is an amenable number.

202121001221 is a deficient number, since it is larger than the sum of its proper divisors (1).

202121001221 is an equidigital number, since it uses as much as digits as its factorization.

202121001221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 202121001221 its reverse (122100121202), we get a palindrome (324221122423).

The spelling of 202121001221 in words is "two hundred two billion, one hundred twenty-one million, one thousand, two hundred twenty-one".