631231 has 4 divisors (see below), whose sum is σ = 639952. Its totient is φ = 622512.

The previous prime is 631229. The next prime is 631247. The reversal of 631231 is 132136.

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

It is a cyclic number.

It is not a de Polignac number, because 631231 - 2¹ = 631229 is a prime.

It is a super-2 number, since 2×631231² = 796905150722, which contains 22 as substring.

It is the 795-th Hogben number.

It is a Duffinian number.

631231 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (631271) by changing a digit.

It is a nontrivial repunit in base 794.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4251 + ... + 4396.

It is an arithmetic number, because the mean of its divisors is an integer number (159988).

2⁶³¹²³¹ is an apocalyptic number.

631231 is a deficient number, since it is larger than the sum of its proper divisors (8721).

631231 is an equidigital number, since it uses as much as digits as its factorization.

631231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8720.

The product of its digits is 108, while the sum is 16.

The square root of 631231 is about 794.5004719948. The cubic root of 631231 is about 85.7819879128.

Adding to 631231 its reverse (132136), we get a palindrome (763367).

The spelling of 631231 in words is "six hundred thirty-one thousand, two hundred thirty-one".