121558889 has 2 divisors, whose sum is σ = 121558890. Its totient is φ = 121558888.

The previous prime is 121558883. The next prime is 121558897. The reversal of 121558889 is 988855121.

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., 103876864 + 17682025 = 10192^2 + 4205^2 .

It is an emirp because it is prime and its reverse (988855121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 121558889 - 2²⁴ = 104781673 is a prime.

It is not a weakly prime, because it can be changed into another prime (121558883) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60779444 + 60779445.

It is an arithmetic number, because the mean of its divisors is an integer number (60779445).

Almost surely, 2^121558889 is an apocalyptic number.

It is an amenable number.

121558889 is a deficient number, since it is larger than the sum of its proper divisors (1).

121558889 is an equidigital number, since it uses as much as digits as its factorization.

121558889 is an evil number, because the sum of its binary digits is even.

The product of its digits is 230400, while the sum is 47.

The square root of 121558889 is about 11025.3747782105. The cubic root of 121558889 is about 495.3690938310.

The spelling of 121558889 in words is "one hundred twenty-one million, five hundred fifty-eight thousand, eight hundred eighty-nine".