121216189 has 2 divisors, whose sum is σ = 121216190. Its totient is φ = 121216188.

The previous prime is 121216177. The next prime is 121216217. The reversal of 121216189 is 981612121.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 117548964 + 3667225 = 10842^2 + 1915^2 .

It is a cyclic number.

It is not a de Polignac number, because 121216189 - 2⁵ = 121216157 is a prime.

It is a Chen prime.

It is an alternating number because its digits alternate between odd and even.

It is a self number, because there is not a number n which added to its sum of digits gives 121216189.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121216129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60608094 + 60608095.

It is an arithmetic number, because the mean of its divisors is an integer number (60608095).

Almost surely, 2^121216189 is an apocalyptic number.

It is an amenable number.

121216189 is a deficient number, since it is larger than the sum of its proper divisors (1).

121216189 is an equidigital number, since it uses as much as digits as its factorization.

121216189 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1728, while the sum is 31.

The square root of 121216189 is about 11009.8223873049. The cubic root of 121216189 is about 494.9031392288.

The spelling of 121216189 in words is "one hundred twenty-one million, two hundred sixteen thousand, one hundred eighty-nine".