121221220189 has 2 divisors, whose sum is σ = 121221220190. Its totient is φ = 121221220188.

The previous prime is 121221220177. The next prime is 121221220213. The reversal of 121221220189 is 981022122121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 89347188100 + 31874032089 = 298910^2 + 178533^2 .

It is a cyclic number.

It is not a de Polignac number, because 121221220189 - 2⁵ = 121221220157 is a prime.

It is a super-2 number, since 2×121221220189² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 121221220189.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121221020189) 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, 60610610094 + 60610610095.

It is an arithmetic number, because the mean of its divisors is an integer number (60610610095).

Almost surely, 2^121221220189 is an apocalyptic number.

It is an amenable number.

121221220189 is a deficient number, since it is larger than the sum of its proper divisors (1).

121221220189 is an equidigital number, since it uses as much as digits as its factorization.

121221220189 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2304, while the sum is 31.

The spelling of 121221220189 in words is "one hundred twenty-one billion, two hundred twenty-one million, two hundred twenty thousand, one hundred eighty-nine".