31313223 has 12 divisors (see below), whose sum is σ = 46905768. Its totient is φ = 20875320.

The previous prime is 31313221. The next prime is 31313239. The reversal of 31313223 is 32231313.

It is not a de Polignac number, because 31313223 - 2¹ = 31313221 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31313196 and 31313205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31313221) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 64188 + ... + 64673.

It is an arithmetic number, because the mean of its divisors is an integer number (3908814).

Almost surely, 2^31313223 is an apocalyptic number.

31313223 is a deficient number, since it is larger than the sum of its proper divisors (15592545).

31313223 is an equidigital number, since it uses as much as digits as its factorization.

31313223 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128876 (or 128864 counting only the distinct ones).

The product of its digits is 324, while the sum is 18.

The square root of 31313223 is about 5595.8219235426. The cubic root of 31313223 is about 315.1925353551.

Adding to 31313223 its reverse (32231313), we get a palindrome (63544536).

The spelling of 31313223 in words is "thirty-one million, three hundred thirteen thousand, two hundred twenty-three".