12557581 has 4 divisors (see below), whose sum is σ = 12564700. Its totient is φ = 12550464.

The previous prime is 12557569. The next prime is 12557593. The reversal of 12557581 is 18575521.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is an interprime number because it is at equal distance from previous prime (12557569) and next prime (12557593).

It can be written as a sum of positive squares in 2 ways, for example, as 6456681 + 6100900 = 2541^2 + 2470^2 .

It is a cyclic number.

It is not a de Polignac number, because 12557581 - 2⁵ = 12557549 is a prime.

It is a super-2 number, since 2×12557581² = 315385681143122, which contains 22 as substring.

It is a Duffinian number.

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 3 ways as a sum of consecutive naturals, for example, 1285 + ... + 5173.

It is an arithmetic number, because the mean of its divisors is an integer number (3141175).

Almost surely, 2^12557581 is an apocalyptic number.

It is an amenable number.

12557581 is a deficient number, since it is larger than the sum of its proper divisors (7119).

12557581 is an equidigital number, since it uses as much as digits as its factorization.

12557581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7118.

The product of its digits is 14000, while the sum is 34.

The square root of 12557581 is about 3543.6677327312. The cubic root of 12557581 is about 232.4352523293.

It can be divided in two parts, 1255 and 7581, that added together give a square (8836 = 94²).

The spelling of 12557581 in words is "twelve million, five hundred fifty-seven thousand, five hundred eighty-one".