12131638 has 4 divisors (see below), whose sum is σ = 18197460. Its totient is φ = 6065818.

The previous prime is 12131629. The next prime is 12131641. The reversal of 12131638 is 83613121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 83613121 = 83 ⋅1007387.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3032908 + ... + 3032911.

It is an arithmetic number, because the mean of its divisors is an integer number (4549365).

Almost surely, 2^12131638 is an apocalyptic number.

12131638 is a deficient number, since it is larger than the sum of its proper divisors (6065822).

12131638 is an equidigital number, since it uses as much as digits as its factorization.

12131638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6065821.

The product of its digits is 864, while the sum is 25.

The square root of 12131638 is about 3483.0501001278. The cubic root of 12131638 is about 229.7769608446.

Adding to 12131638 its reverse (83613121), we get a palindrome (95744759).

It can be divided in two parts, 12131 and 638, that added together give a square (12769 = 113²).

The spelling of 12131638 in words is "twelve million, one hundred thirty-one thousand, six hundred thirty-eight".