31423231 has 4 divisors (see below), whose sum is σ = 35912272. Its totient is φ = 26934192.

The previous prime is 31423187. The next prime is 31423237. The reversal of 31423231 is 13232413.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13232413 = 113 ⋅117101.

It is a cyclic number.

It is not a de Polignac number, because 31423231 - 2⁷ = 31423103 is a prime.

It is a super-2 number, since 2×31423231² = 1974838892958722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31423199 and 31423208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31423237) 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, 2244510 + ... + 2244523.

It is an arithmetic number, because the mean of its divisors is an integer number (8978068).

Almost surely, 2^31423231 is an apocalyptic number.

31423231 is a deficient number, since it is larger than the sum of its proper divisors (4489041).

31423231 is an equidigital number, since it uses as much as digits as its factorization.

31423231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4489040.

The product of its digits is 432, while the sum is 19.

The square root of 31423231 is about 5605.6427820545. The cubic root of 31423231 is about 315.5612100082.

Adding to 31423231 its reverse (13232413), we get a palindrome (44655644).

The spelling of 31423231 in words is "thirty-one million, four hundred twenty-three thousand, two hundred thirty-one".