12318991 has 2 divisors, whose sum is σ = 12318992. Its totient is φ = 12318990.

The previous prime is 12318979. The next prime is 12319061. The reversal of 12318991 is 19981321.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 12318991 - 2¹¹ = 12316943 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12318091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6159495 + 6159496.

It is an arithmetic number, because the mean of its divisors is an integer number (6159496).

Almost surely, 2^12318991 is an apocalyptic number.

12318991 is a deficient number, since it is larger than the sum of its proper divisors (1).

12318991 is an equidigital number, since it uses as much as digits as its factorization.

12318991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3888, while the sum is 34.

The square root of 12318991 is about 3509.8420192368. The cubic root of 12318991 is about 230.9537647263.

The spelling of 12318991 in words is "twelve million, three hundred eighteen thousand, nine hundred ninety-one".