12181438 has 4 divisors (see below), whose sum is σ = 18272160. Its totient is φ = 6090718.

The previous prime is 12181423. The next prime is 12181447. The reversal of 12181438 is 83418121.

It is a semiprime because it is the product of two primes.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3045358 + ... + 3045361.

It is an arithmetic number, because the mean of its divisors is an integer number (4568040).

Almost surely, 2^12181438 is an apocalyptic number.

12181438 is a deficient number, since it is larger than the sum of its proper divisors (6090722).

12181438 is an equidigital number, since it uses as much as digits as its factorization.

12181438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6090721.

The product of its digits is 1536, while the sum is 28.

The square root of 12181438 is about 3490.1916852803. The cubic root of 12181438 is about 230.0909407234.

Adding to 12181438 its reverse (83418121), we get a palindrome (95599559).

The spelling of 12181438 in words is "twelve million, one hundred eighty-one thousand, four hundred thirty-eight".