31311223 has 2 divisors, whose sum is σ = 31311224. Its totient is φ = 31311222.

The previous prime is 31311197. The next prime is 31311251. The reversal of 31311223 is 32211313.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 31311223 - 2⁵ = 31311191 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31311197 and 31311206.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31311253) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15655611 + 15655612.

It is an arithmetic number, because the mean of its divisors is an integer number (15655612).

Almost surely, 2^31311223 is an apocalyptic number.

31311223 is a deficient number, since it is larger than the sum of its proper divisors (1).

31311223 is an equidigital number, since it uses as much as digits as its factorization.

31311223 is an odious number, because the sum of its binary digits is odd.

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

The square root of 31311223 is about 5595.6432159315. The cubic root of 31311223 is about 315.1858246812.

Adding to 31311223 its reverse (32211313), we get a palindrome (63522536).

The spelling of 31311223 in words is "thirty-one million, three hundred eleven thousand, two hundred twenty-three".