231211139 has 4 divisors (see below), whose sum is σ = 231432600. Its totient is φ = 230989680.

The previous prime is 231211109. The next prime is 231211153. The reversal of 231211139 is 931112132.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-231211139 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (231211109) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 109157 + ... + 111254.

It is an arithmetic number, because the mean of its divisors is an integer number (57858150).

Almost surely, 2^231211139 is an apocalyptic number.

231211139 is a deficient number, since it is larger than the sum of its proper divisors (221461).

231211139 is a wasteful number, since it uses less digits than its factorization.

231211139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 221460.

The product of its digits is 324, while the sum is 23.

The square root of 231211139 is about 15205.6285302516. The cubic root of 231211139 is about 613.7661286089.

The spelling of 231211139 in words is "two hundred thirty-one million, two hundred eleven thousand, one hundred thirty-nine".