12865817 has 4 divisors (see below), whose sum is σ = 12873600. Its totient is φ = 12858036.

The previous prime is 12865813. The next prime is 12865829. The reversal of 12865817 is 71856821.

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 a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 12865817 - 2² = 12865813 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12865813) 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, 317 + ... + 5082.

It is an arithmetic number, because the mean of its divisors is an integer number (3218400).

Almost surely, 2^12865817 is an apocalyptic number.

It is an amenable number.

12865817 is a deficient number, since it is larger than the sum of its proper divisors (7783).

12865817 is an equidigital number, since it uses as much as digits as its factorization.

12865817 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7782.

The product of its digits is 26880, while the sum is 38.

The square root of 12865817 is about 3586.8951754965. The cubic root of 12865817 is about 234.3216714698.

It can be divided in two parts, 128658 and 17, that multiplied together give a triangular number (2187186 = T₂₀₉₁).

The spelling of 12865817 in words is "twelve million, eight hundred sixty-five thousand, eight hundred seventeen".