312123139 has 2 divisors, whose sum is σ = 312123140. Its totient is φ = 312123138.

The previous prime is 312123137. The next prime is 312123151. The reversal of 312123139 is 931321213.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 312123139 - 2¹ = 312123137 is a prime.

Together with 312123137, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (312123137) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 156061569 + 156061570.

It is an arithmetic number, because the mean of its divisors is an integer number (156061570).

Almost surely, 2^312123139 is an apocalyptic number.

312123139 is a deficient number, since it is larger than the sum of its proper divisors (1).

312123139 is an equidigital number, since it uses as much as digits as its factorization.

312123139 is an evil number, because the sum of its binary digits is even.

The product of its digits is 972, while the sum is 25.

The square root of 312123139 is about 17667.0070753368. The cubic root of 312123139 is about 678.3315055815.

The spelling of 312123139 in words is "three hundred twelve million, one hundred twenty-three thousand, one hundred thirty-nine".