1221020102221 has 2 divisors, whose sum is σ = 1221020102222. Its totient is φ = 1221020102220.

The previous prime is 1221020102153. The next prime is 1221020102287. The reversal of 1221020102221 is 1222010201221.

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., 1219668436996 + 1351665225 = 1104386^2 + 36765^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221020102221 - 2²¹ = 1221018005069 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1221020102195 and 1221020102204.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221020162221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610510051110 + 610510051111.

It is an arithmetic number, because the mean of its divisors is an integer number (610510051111).

Almost surely, 2^{1221020102221} is an apocalyptic number.

It is an amenable number.

1221020102221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221020102221 is an equidigital number, since it uses as much as digits as its factorization.

1221020102221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 1221020102221 its reverse (1222010201221), we get a palindrome (2443030303442).

The spelling of 1221020102221 in words is "one trillion, two hundred twenty-one billion, twenty million, one hundred two thousand, two hundred twenty-one".