231531247 has 2 divisors, whose sum is σ = 231531248. Its totient is φ = 231531246.

The previous prime is 231531241. The next prime is 231531269. The reversal of 231531247 is 742135132.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 231531247 - 2⁷ = 231531119 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (231531241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115765623 + 115765624.

It is an arithmetic number, because the mean of its divisors is an integer number (115765624).

Almost surely, 2^231531247 is an apocalyptic number.

231531247 is a deficient number, since it is larger than the sum of its proper divisors (1).

231531247 is an equidigital number, since it uses as much as digits as its factorization.

231531247 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5040, while the sum is 28.

The square root of 231531247 is about 15216.1508601880. The cubic root of 231531247 is about 614.0492476776.

Adding to 231531247 its reverse (742135132), we get a palindrome (973666379).

The spelling of 231531247 in words is "two hundred thirty-one million, five hundred thirty-one thousand, two hundred forty-seven".