121916321 has 2 divisors, whose sum is σ = 121916322. Its totient is φ = 121916320.

The previous prime is 121916303. The next prime is 121916371. The reversal of 121916321 is 123619121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 79405921 + 42510400 = 8911^2 + 6520^2 .

It is a cyclic number.

It is not a de Polignac number, because 121916321 - 2⁶ = 121916257 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (121916371) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60958160 + 60958161.

It is an arithmetic number, because the mean of its divisors is an integer number (60958161).

Almost surely, 2^121916321 is an apocalyptic number.

It is an amenable number.

121916321 is a deficient number, since it is larger than the sum of its proper divisors (1).

121916321 is an equidigital number, since it uses as much as digits as its factorization.

121916321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 648, while the sum is 26.

The square root of 121916321 is about 11041.5723970819. The cubic root of 121916321 is about 495.8541468152.

The spelling of 121916321 in words is "one hundred twenty-one million, nine hundred sixteen thousand, three hundred twenty-one".