12315815 has 4 divisors (see below), whose sum is σ = 14778984. Its totient is φ = 9852648.

The previous prime is 12315811. The next prime is 12315829. The reversal of 12315815 is 51851321.

It is a happy number.

12315815 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 51851321 = 509 ⋅101869.

It is a cyclic number.

It is not a de Polignac number, because 12315815 - 2² = 12315811 is a prime.

It is a super-2 number, since 2×12315815² = 303358598228450, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12315811) 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, 1231577 + ... + 1231586.

It is an arithmetic number, because the mean of its divisors is an integer number (3694746).

Almost surely, 2^12315815 is an apocalyptic number.

12315815 is a deficient number, since it is larger than the sum of its proper divisors (2463169).

12315815 is an equidigital number, since it uses as much as digits as its factorization.

12315815 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2463168.

The product of its digits is 1200, while the sum is 26.

The square root of 12315815 is about 3509.3895480553. The cubic root of 12315815 is about 230.9339153679.

The spelling of 12315815 in words is "twelve million, three hundred fifteen thousand, eight hundred fifteen".