12131618 has 4 divisors (see below), whose sum is σ = 18197430. Its totient is φ = 6065808.

The previous prime is 12131573. The next prime is 12131621. The reversal of 12131618 is 81613121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 81613121 = 127 ⋅642623.

It can be written as a sum of positive squares in only one way, i.e., 8720209 + 3411409 = 2953^2 + 1847^2 .

It is a junction number, because it is equal to n+sod(n) for n = 12131593 and 12131602.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3032903 + ... + 3032906.

Almost surely, 2^12131618 is an apocalyptic number.

12131618 is a deficient number, since it is larger than the sum of its proper divisors (6065812).

12131618 is an equidigital number, since it uses as much as digits as its factorization.

12131618 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6065811.

The product of its digits is 288, while the sum is 23.

The square root of 12131618 is about 3483.0472290797. The cubic root of 12131618 is about 229.7768345758.

Adding to 12131618 its reverse (81613121), we get a palindrome (93744739).

The spelling of 12131618 in words is "twelve million, one hundred thirty-one thousand, six hundred eighteen".