121312309 has 4 divisors (see below), whose sum is σ = 121479904. Its totient is φ = 121144716.

The previous prime is 121312297. The next prime is 121312339. The reversal of 121312309 is 903213121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 903213121 = 53 ⋅17041757.

It is a cyclic number.

It is not a de Polignac number, because 121312309 - 2⁷ = 121312181 is a prime.

It is a super-2 number, since 2×121312309² = 29433352629822962, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 121312309.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121312339) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 82707 + ... + 84160.

It is an arithmetic number, because the mean of its divisors is an integer number (30369976).

Almost surely, 2^121312309 is an apocalyptic number.

It is an amenable number.

121312309 is a deficient number, since it is larger than the sum of its proper divisors (167595).

121312309 is an equidigital number, since it uses as much as digits as its factorization.

121312309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167594.

The product of its (nonzero) digits is 324, while the sum is 22.

The square root of 121312309 is about 11014.1867153231. The cubic root of 121312309 is about 495.0339180241.

The spelling of 121312309 in words is "one hundred twenty-one million, three hundred twelve thousand, three hundred nine".