121158721 has 2 divisors, whose sum is σ = 121158722. Its totient is φ = 121158720.

The previous prime is 121158707. The next prime is 121158761. The reversal of 121158721 is 127851121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 104837121 + 16321600 = 10239^2 + 4040^2 .

It is an emirp because it is prime and its reverse (127851121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 121158721 - 2⁷ = 121158593 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 121158721.

It is not a weakly prime, because it can be changed into another prime (121158701) 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, 60579360 + 60579361.

It is an arithmetic number, because the mean of its divisors is an integer number (60579361).

Almost surely, 2^121158721 is an apocalyptic number.

It is an amenable number.

121158721 is a deficient number, since it is larger than the sum of its proper divisors (1).

121158721 is an equidigital number, since it uses as much as digits as its factorization.

121158721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1120, while the sum is 28.

The square root of 121158721 is about 11007.2122265358. The cubic root of 121158721 is about 494.8249164831.

The spelling of 121158721 in words is "one hundred twenty-one million, one hundred fifty-eight thousand, seven hundred twenty-one".