231139247 has 4 divisors (see below), whose sum is σ = 231452760. Its totient is φ = 230825736.

The previous prime is 231139241. The next prime is 231139253. The reversal of 231139247 is 742931132.

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

It is an interprime number because it is at equal distance from previous prime (231139241) and next prime (231139253).

It is a cyclic number.

It is not a de Polignac number, because 231139247 - 2⁴ = 231139231 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231139241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 155648 + ... + 157125.

It is an arithmetic number, because the mean of its divisors is an integer number (57863190).

Almost surely, 2^231139247 is an apocalyptic number.

231139247 is a deficient number, since it is larger than the sum of its proper divisors (313513).

231139247 is an equidigital number, since it uses as much as digits as its factorization.

231139247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 313512.

The product of its digits is 9072, while the sum is 32.

The square root of 231139247 is about 15203.2643534209. The cubic root of 231139247 is about 613.7025079015.

The spelling of 231139247 in words is "two hundred thirty-one million, one hundred thirty-nine thousand, two hundred forty-seven".