123121189 has 2 divisors, whose sum is σ = 123121190. Its totient is φ = 123121188.

The previous prime is 123121183. The next prime is 123121217. The reversal of 123121189 is 981121321.

It is an a-pointer prime, because the next prime (123121217) can be obtained adding 123121189 to its sum of digits (28).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 103184964 + 19936225 = 10158^2 + 4465^2 .

It is a cyclic number.

It is not a de Polignac number, because 123121189 - 2⁹ = 123120677 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (123121183) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61560594 + 61560595.

It is an arithmetic number, because the mean of its divisors is an integer number (61560595).

Almost surely, 2^123121189 is an apocalyptic number.

It is an amenable number.

123121189 is a deficient number, since it is larger than the sum of its proper divisors (1).

123121189 is an equidigital number, since it uses as much as digits as its factorization.

123121189 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 864, while the sum is 28.

The square root of 123121189 is about 11095.9987833453. The cubic root of 123121189 is about 497.4822619367.

The spelling of 123121189 in words is "one hundred twenty-three million, one hundred twenty-one thousand, one hundred eighty-nine".