121918109 has 2 divisors, whose sum is σ = 121918110. Its totient is φ = 121918108.

The previous prime is 121918061. The next prime is 121918129. The reversal of 121918109 is 901819121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 78818884 + 43099225 = 8878^2 + 6565^2 .

It is a cyclic number.

It is not a de Polignac number, because 121918109 - 2¹⁶ = 121852573 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121918129) 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, 60959054 + 60959055.

It is an arithmetic number, because the mean of its divisors is an integer number (60959055).

Almost surely, 2^121918109 is an apocalyptic number.

It is an amenable number.

121918109 is a deficient number, since it is larger than the sum of its proper divisors (1).

121918109 is an equidigital number, since it uses as much as digits as its factorization.

121918109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1296, while the sum is 32.

The square root of 121918109 is about 11041.6533635140. The cubic root of 121918109 is about 495.8565708354.

The spelling of 121918109 in words is "one hundred twenty-one million, nine hundred eighteen thousand, one hundred nine".