231642139 has 2 divisors, whose sum is σ = 231642140. Its totient is φ = 231642138.

The previous prime is 231642101. The next prime is 231642143. The reversal of 231642139 is 931246132.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 231642139 - 2¹³ = 231633947 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 231642139.

It is not a weakly prime, because it can be changed into another prime (231642239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115821069 + 115821070.

It is an arithmetic number, because the mean of its divisors is an integer number (115821070).

Almost surely, 2^231642139 is an apocalyptic number.

231642139 is a deficient number, since it is larger than the sum of its proper divisors (1).

231642139 is an equidigital number, since it uses as much as digits as its factorization.

231642139 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7776, while the sum is 31.

The square root of 231642139 is about 15219.7943152987. The cubic root of 231642139 is about 614.1472650898.

The spelling of 231642139 in words is "two hundred thirty-one million, six hundred forty-two thousand, one hundred thirty-nine".