12665865 has 32 divisors (see below), whose sum is σ = 21098880. Its totient is φ = 6483456.

The previous prime is 12665839. The next prime is 12665869. The reversal of 12665865 is 56856621.

It is not a de Polignac number, because 12665865 - 2¹¹ = 12663817 is a prime.

It is not an unprimeable number, because it can be changed into a prime (12665869) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 46951 + ... + 47219.

It is an arithmetic number, because the mean of its divisors is an integer number (659340).

Almost surely, 2^12665865 is an apocalyptic number.

12665865 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

12665865 is a deficient number, since it is larger than the sum of its proper divisors (8433015).

12665865 is a wasteful number, since it uses less digits than its factorization.

12665865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 393.

The product of its digits is 86400, while the sum is 39.

The square root of 12665865 is about 3558.9134577846. The cubic root of 12665865 is about 233.1014374094.

It can be divided in two parts, 12665 and 865, that added together give a triangular number (13530 = T₁₆₄).

The spelling of 12665865 in words is "twelve million, six hundred sixty-five thousand, eight hundred sixty-five".