12565866 has 48 divisors (see below), whose sum is σ = 27234144. Its totient is φ = 3861792.

The previous prime is 12565853. The next prime is 12565871. The reversal of 12565866 is 66856521.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 117385 + ... + 117491.

It is an arithmetic number, because the mean of its divisors is an integer number (567378).

Almost surely, 2^12565866 is an apocalyptic number.

12565866 is an abundant number, since it is smaller than the sum of its proper divisors (14668278).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

12565866 is a wasteful number, since it uses less digits than its factorization.

12565866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 195 (or 172 counting only the distinct ones).

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

The square root of 12565866 is about 3544.8365265552. The cubic root of 12565866 is about 232.4863583163.

It can be divided in two parts, 12565 and 866, that added together give a palindrome (13431).

The spelling of 12565866 in words is "twelve million, five hundred sixty-five thousand, eight hundred sixty-six".