121512509 has 2 divisors, whose sum is σ = 121512510. Its totient is φ = 121512508.

The previous prime is 121512497. The next prime is 121512511. The reversal of 121512509 is 905215121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 117787609 + 3724900 = 10853^2 + 1930^2 .

It is a cyclic number.

It is not a de Polignac number, because 121512509 - 2⁴ = 121512493 is a prime.

Together with 121512511, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121502509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60756254 + 60756255.

It is an arithmetic number, because the mean of its divisors is an integer number (60756255).

Almost surely, 2^121512509 is an apocalyptic number.

It is an amenable number.

121512509 is a deficient number, since it is larger than the sum of its proper divisors (1).

121512509 is an equidigital number, since it uses as much as digits as its factorization.

121512509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 900, while the sum is 26.

The square root of 121512509 is about 11023.2712476832. The cubic root of 121512509 is about 495.3060842027.

The spelling of 121512509 in words is "one hundred twenty-one million, five hundred twelve thousand, five hundred nine".