1221120822121 has 2 divisors, whose sum is σ = 1221120822122. Its totient is φ = 1221120822120.

The previous prime is 1221120822071. The next prime is 1221120822127. The reversal of 1221120822121 is 1212280211221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1182571426521 + 38549395600 = 1087461^2 + 196340^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221120822121 - 2¹⁵ = 1221120789353 is a prime.

It is a super-2 number, since 2×1221120822121² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1221120822127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610560411060 + 610560411061.

It is an arithmetic number, because the mean of its divisors is an integer number (610560411061).

Almost surely, 2^{1221120822121} is an apocalyptic number.

It is an amenable number.

1221120822121 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221120822121 is an equidigital number, since it uses as much as digits as its factorization.

1221120822121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 512, while the sum is 25.

The spelling of 1221120822121 in words is "one trillion, two hundred twenty-one billion, one hundred twenty million, eight hundred twenty-two thousand, one hundred twenty-one".