12261638 has 4 divisors (see below), whose sum is σ = 18392460. Its totient is φ = 6130818.

The previous prime is 12261617. The next prime is 12261649. The reversal of 12261638 is 83616221.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 83616221 = 13 ⋅6432017.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 12261638.

It is a congruent number.

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, 3065408 + ... + 3065411.

It is an arithmetic number, because the mean of its divisors is an integer number (4598115).

Almost surely, 2^12261638 is an apocalyptic number.

12261638 is a deficient number, since it is larger than the sum of its proper divisors (6130822).

12261638 is an equidigital number, since it uses as much as digits as its factorization.

12261638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6130821.

The product of its digits is 3456, while the sum is 29.

The square root of 12261638 is about 3501.6621767384. The cubic root of 12261638 is about 230.5947932079.

Adding to 12261638 its reverse (83616221), we get a palindrome (95877859).

The spelling of 12261638 in words is "twelve million, two hundred sixty-one thousand, six hundred thirty-eight".