12865566 has 64 divisors (see below), whose sum is σ = 32044032. Its totient is φ = 3359232.

The previous prime is 12865553. The next prime is 12865613. The reversal of 12865566 is 66556821.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 26175 + ... + 26661.

It is an arithmetic number, because the mean of its divisors is an integer number (500688).

Almost surely, 2^12865566 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 12865566, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16022016).

12865566 is an abundant number, since it is smaller than the sum of its proper divisors (19178466).

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

12865566 is a wasteful number, since it uses less digits than its factorization.

12865566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 553.

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

The square root of 12865566 is about 3586.8601868487. The cubic root of 12865566 is about 234.3201476613.

It can be divided in two parts, 12865 and 566, that added together give a palindrome (13431).

The spelling of 12865566 in words is "twelve million, eight hundred sixty-five thousand, five hundred sixty-six".