12918231 has 8 divisors (see below), whose sum is σ = 19138160. Its totient is φ = 8612136.

The previous prime is 12918229. The next prime is 12918259. The reversal of 12918231 is 13281921.

It is not a de Polignac number, because 12918231 - 2¹ = 12918229 is a prime.

It is a super-2 number, since 2×12918231² = 333761384338722, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 478453 = 12918231 / (1 + 2 + 9 + 1 + 8 + 2 + 3 + 1).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12918195 and 12918204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12918281) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 239200 + ... + 239253.

It is an arithmetic number, because the mean of its divisors is an integer number (2392270).

Almost surely, 2^12918231 is an apocalyptic number.

12918231 is a deficient number, since it is larger than the sum of its proper divisors (6219929).

12918231 is an equidigital number, since it uses as much as digits as its factorization.

12918231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 478462 (or 478456 counting only the distinct ones).

The product of its digits is 864, while the sum is 27.

The square root of 12918231 is about 3594.1940682161. The cubic root of 12918231 is about 234.6394410438.

The spelling of 12918231 in words is "twelve million, nine hundred eighteen thousand, two hundred thirty-one".