221002202020121 has 2 divisors, whose sum is σ = 221002202020122. Its totient is φ = 221002202020120.

The previous prime is 221002202020099. The next prime is 221002202020123. The reversal of 221002202020121 is 121020202200122.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 184316600505625 + 36685601514496 = 13576325^2 + 6056864^2 .

It is a cyclic number.

It is not a de Polignac number, because 221002202020121 - 2⁶ = 221002202020057 is a prime.

It is a super-2 number, since 2×221002202020121² (a number of 29 digits) contains 22 as substring.

Together with 221002202020123, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 221002202020121.

It is not a weakly prime, because it can be changed into another prime (221002202020123) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110501101010060 + 110501101010061.

It is an arithmetic number, because the mean of its divisors is an integer number (110501101010061).

Almost surely, 2^{221002202020121} is an apocalyptic number.

It is an amenable number.

221002202020121 is a deficient number, since it is larger than the sum of its proper divisors (1).

221002202020121 is an equidigital number, since it uses as much as digits as its factorization.

221002202020121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 221002202020121 its reverse (121020202200122), we get a palindrome (342022404220243).

The spelling of 221002202020121 in words is "two hundred twenty-one trillion, two billion, two hundred two million, twenty thousand, one hundred twenty-one".