31122313 has 4 divisors (see below), whose sum is σ = 31152708. Its totient is φ = 31091920.

The previous prime is 31122293. The next prime is 31122331. The reversal of 31122313 is 31322113.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 31322113 = 23 ⋅1361831.

It can be written as a sum of positive squares in 2 ways, for example, as 23011209 + 8111104 = 4797^2 + 2848^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31122313 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31122373) 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, 13606 + ... + 15727.

It is an arithmetic number, because the mean of its divisors is an integer number (7788177).

Almost surely, 2^31122313 is an apocalyptic number.

It is an amenable number.

31122313 is a deficient number, since it is larger than the sum of its proper divisors (30395).

31122313 is a wasteful number, since it uses less digits than its factorization.

31122313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30394.

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

The square root of 31122313 is about 5578.7375812096. The cubic root of 31122313 is about 314.5506754085.

Adding to 31122313 its reverse (31322113), we get a palindrome (62444426).

The spelling of 31122313 in words is "thirty-one million, one hundred twenty-two thousand, three hundred thirteen".