121715989 has 2 divisors, whose sum is σ = 121715990. Its totient is φ = 121715988.

The previous prime is 121715959. The next prime is 121715999. The reversal of 121715989 is 989517121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 110040100 + 11675889 = 10490^2 + 3417^2 .

It is a cyclic number.

It is not a de Polignac number, because 121715989 - 2¹¹ = 121713941 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121715959) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60857994 + 60857995.

It is an arithmetic number, because the mean of its divisors is an integer number (60857995).

Almost surely, 2^121715989 is an apocalyptic number.

It is an amenable number.

121715989 is a deficient number, since it is larger than the sum of its proper divisors (1).

121715989 is an equidigital number, since it uses as much as digits as its factorization.

121715989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 45360, while the sum is 43.

The square root of 121715989 is about 11032.4969521863. The cubic root of 121715989 is about 495.5824032921.

The spelling of 121715989 in words is "one hundred twenty-one million, seven hundred fifteen thousand, nine hundred eighty-nine".