12566399 has 4 divisors (see below), whose sum is σ = 12594120. Its totient is φ = 12538680.

The previous prime is 12566369. The next prime is 12566419. The reversal of 12566399 is 99366521.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 99366521 = 83 ⋅1197187.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12566399 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12566329) 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, 13169 + ... + 14090.

It is an arithmetic number, because the mean of its divisors is an integer number (3148530).

Almost surely, 2^12566399 is an apocalyptic number.

12566399 is a deficient number, since it is larger than the sum of its proper divisors (27721).

12566399 is an equidigital number, since it uses as much as digits as its factorization.

12566399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27720.

The product of its digits is 87480, while the sum is 41.

The square root of 12566399 is about 3544.9117055295. The cubic root of 12566399 is about 232.4896453553.

The spelling of 12566399 in words is "twelve million, five hundred sixty-six thousand, three hundred ninety-nine".