31323213 has 16 divisors (see below), whose sum is σ = 46542400. Its totient is φ = 20820240.

The previous prime is 31323203. The next prime is 31323223. The reversal of 31323213 is 31232313.

It is an interprime number because it is at equal distance from previous prime (31323203) and next prime (31323223).

It is not a de Polignac number, because 31323213 - 2⁵ = 31323181 is a prime.

It is a super-2 number, since 2×31323213² = 1962287345286738, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31323203) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8703 + ... + 11763.

It is an arithmetic number, because the mean of its divisors is an integer number (2908900).

Almost surely, 2^31323213 is an apocalyptic number.

It is an amenable number.

31323213 is a deficient number, since it is larger than the sum of its proper divisors (15219187).

31323213 is a wasteful number, since it uses less digits than its factorization.

31323213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3449 (or 3443 counting only the distinct ones).

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

The square root of 31323213 is about 5596.7144826228. The cubic root of 31323213 is about 315.2260508941.

Adding to 31323213 its reverse (31232313), we get a palindrome (62555526).

The spelling of 31323213 in words is "thirty-one million, three hundred twenty-three thousand, two hundred thirteen".