331231 has 2 divisors, whose sum is σ = 331232. Its totient is φ = 331230.

The previous prime is 331217. The next prime is 331241. The reversal of 331231 is 132133.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 331231 - 2⁹ = 330719 is a prime.

It is a super-2 number, since 2×331231² = 219427950722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (331241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 165615 + 165616.

It is an arithmetic number, because the mean of its divisors is an integer number (165616).

2³³¹²³¹ is an apocalyptic number.

331231 is a deficient number, since it is larger than the sum of its proper divisors (1).

331231 is an equidigital number, since it uses as much as digits as its factorization.

331231 is an evil number, because the sum of its binary digits is even.

The product of its digits is 54, while the sum is 13.

The square root of 331231 is about 575.5267152791. The cubic root of 331231 is about 69.1900522526.

Adding to 331231 its reverse (132133), we get a palindrome (463364).

It can be divided in two parts, 33123 and 1, that added together give a square (33124 = 182²).

The spelling of 331231 in words is "three hundred thirty-one thousand, two hundred thirty-one".