231312139 has 2 divisors, whose sum is σ = 231312140. Its totient is φ = 231312138.

The previous prime is 231312121. The next prime is 231312143. The reversal of 231312139 is 931213132.

231312139 is digitally balanced in base 2, 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 231312139 - 2¹¹ = 231310091 is a prime.

It is not a weakly prime, because it can be changed into another prime (231322139) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115656069 + 115656070.

It is an arithmetic number, because the mean of its divisors is an integer number (115656070).

Almost surely, 2^231312139 is an apocalyptic number.

231312139 is a deficient number, since it is larger than the sum of its proper divisors (1).

231312139 is an equidigital number, since it uses as much as digits as its factorization.

231312139 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 231312139 is about 15208.9493062473. The cubic root of 231312139 is about 613.8554861185.

The spelling of 231312139 in words is "two hundred thirty-one million, three hundred twelve thousand, one hundred thirty-nine".