312111731 has 2 divisors, whose sum is σ = 312111732. Its totient is φ = 312111730.

The previous prime is 312111713. The next prime is 312111749. The reversal of 312111731 is 137111213.

Together with previous prime (312111713) it forms an Ormiston pair, because they use the same digits, order apart.

It is a balanced prime because it is at equal distance from previous prime (312111713) and next prime (312111749).

It is an emirp because it is prime and its reverse (137111213) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-312111731 is a prime.

It is a super-2 number, since 2×312111731² = 194827465255632722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (312111781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 156055865 + 156055866.

It is an arithmetic number, because the mean of its divisors is an integer number (156055866).

Almost surely, 2^312111731 is an apocalyptic number.

312111731 is a deficient number, since it is larger than the sum of its proper divisors (1).

312111731 is an equidigital number, since it uses as much as digits as its factorization.

312111731 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 126, while the sum is 20.

The square root of 312111731 is about 17666.6842106831. The cubic root of 312111731 is about 678.3232412150.

Adding to 312111731 its reverse (137111213), we get a palindrome (449222944).

The spelling of 312111731 in words is "three hundred twelve million, one hundred eleven thousand, seven hundred thirty-one".