121019989 has 2 divisors, whose sum is σ = 121019990. Its totient is φ = 121019988.

The previous prime is 121019981. The next prime is 121019993. The reversal of 121019989 is 989910121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 106708900 + 14311089 = 10330^2 + 3783^2 .

It is an emirp because it is prime and its reverse (989910121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 121019989 - 2³ = 121019981 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121019981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60509994 + 60509995.

It is an arithmetic number, because the mean of its divisors is an integer number (60509995).

Almost surely, 2^121019989 is an apocalyptic number.

It is an amenable number.

121019989 is a deficient number, since it is larger than the sum of its proper divisors (1).

121019989 is an equidigital number, since it uses as much as digits as its factorization.

121019989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11664, while the sum is 40.

The square root of 121019989 is about 11000.9085533878. The cubic root of 121019989 is about 494.6359790076.

The spelling of 121019989 in words is "one hundred twenty-one million, nineteen thousand, nine hundred eighty-nine".