12561518 has 4 divisors (see below), whose sum is σ = 18842280. Its totient is φ = 6280758.

The previous prime is 12561511. The next prime is 12561529. The reversal of 12561518 is 81516521.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 81516521 = 311 ⋅262111.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12561511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3140378 + ... + 3140381.

It is an arithmetic number, because the mean of its divisors is an integer number (4710570).

Almost surely, 2^12561518 is an apocalyptic number.

12561518 is a deficient number, since it is larger than the sum of its proper divisors (6280762).

12561518 is an equidigital number, since it uses as much as digits as its factorization.

12561518 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6280761.

The product of its digits is 2400, while the sum is 29.

The square root of 12561518 is about 3544.2231871032. The cubic root of 12561518 is about 232.4595404989.

The spelling of 12561518 in words is "twelve million, five hundred sixty-one thousand, five hundred eighteen".