121317809 has 2 divisors, whose sum is σ = 121317810. Its totient is φ = 121317808.

The previous prime is 121317799. The next prime is 121317821. The reversal of 121317809 is 908713121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 76387600 + 44930209 = 8740^2 + 6703^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121317809 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (121317409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60658904 + 60658905.

It is an arithmetic number, because the mean of its divisors is an integer number (60658905).

Almost surely, 2^121317809 is an apocalyptic number.

It is an amenable number.

121317809 is a deficient number, since it is larger than the sum of its proper divisors (1).

121317809 is an equidigital number, since it uses as much as digits as its factorization.

121317809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3024, while the sum is 32.

The square root of 121317809 is about 11014.4363904832. The cubic root of 121317809 is about 495.0413991155.

The spelling of 121317809 in words is "one hundred twenty-one million, three hundred seventeen thousand, eight hundred nine".