1002121221221 has 2 divisors, whose sum is σ = 1002121221222. Its totient is φ = 1002121221220.

The previous prime is 1002121221163. The next prime is 1002121221223. The reversal of 1002121221221 is 1221221212001.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 896125396321 + 105995824900 = 946639^2 + 325570^2 .

It is a cyclic number.

It is not a de Polignac number, because 1002121221221 - 2¹⁰ = 1002121220197 is a prime.

Together with 1002121221223, 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 1002121221221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1002121221223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 501060610610 + 501060610611.

It is an arithmetic number, because the mean of its divisors is an integer number (501060610611).

Almost surely, 2^{1002121221221} is an apocalyptic number.

It is an amenable number.

1002121221221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1002121221221 is an equidigital number, since it uses as much as digits as its factorization.

1002121221221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 1002121221221 its reverse (1221221212001), we get a palindrome (2223342433222).

The spelling of 1002121221221 in words is "one trillion, two billion, one hundred twenty-one million, two hundred twenty-one thousand, two hundred twenty-one".