12312991 has 2 divisors, whose sum is σ = 12312992. Its totient is φ = 12312990.

The previous prime is 12312973. The next prime is 12313003. The reversal of 12312991 is 19921321.

12312991 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 12312991 - 2⁵ = 12312959 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12312901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6156495 + 6156496.

It is an arithmetic number, because the mean of its divisors is an integer number (6156496).

Almost surely, 2^12312991 is an apocalyptic number.

12312991 is a deficient number, since it is larger than the sum of its proper divisors (1).

12312991 is an equidigital number, since it uses as much as digits as its factorization.

12312991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 972, while the sum is 28.

The square root of 12312991 is about 3508.9871758101. The cubic root of 12312991 is about 230.9162630720.

The spelling of 12312991 in words is "twelve million, three hundred twelve thousand, nine hundred ninety-one".