12557566 has 16 divisors (see below), whose sum is σ = 21651840. Its totient is φ = 5350680.

The previous prime is 12557561. The next prime is 12557569. The reversal of 12557566 is 66575521.

12557566 is a nontrivial binomial coefficient, being equal to C(5012, 2).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12557561) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1 + ... + 5011.

It is an arithmetic number, because the mean of its divisors is an integer number (1353240).

Almost surely, 2^12557566 is an apocalyptic number.

12557566 is the 5011-st triangular number and also the 2506-th hexagonal number.

12557566 is the 1671-st centered nonagonal number.

12557566 is a deficient number, since it is larger than the sum of its proper divisors (9094274).

12557566 is a wasteful number, since it uses less digits than its factorization.

12557566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5199.

The product of its digits is 63000, while the sum is 37.

The square root of 12557566 is about 3543.6656162793. The cubic root of 12557566 is about 232.4351597814.

The spelling of 12557566 in words is "twelve million, five hundred fifty-seven thousand, five hundred sixty-six".