31123313 has 4 divisors (see below), whose sum is σ = 33517428. Its totient is φ = 28729200.

The previous prime is 31123303. The next prime is 31123319. The reversal of 31123313 is 31332113.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 31332113 = 307 ⋅102059.

It can be written as a sum of positive squares in 2 ways, for example, as 8958049 + 22165264 = 2993^2 + 4708^2 .

It is a cyclic number.

It is not a de Polignac number, because 31123313 - 2²² = 26929009 is a prime.

It is a super-2 number, since 2×31123313² = 1937321224191938, 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 = 31123291 and 31123300.

It is not an unprimeable number, because it can be changed into a prime (31123319) 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, 1197038 + ... + 1197063.

It is an arithmetic number, because the mean of its divisors is an integer number (8379357).

Almost surely, 2^31123313 is an apocalyptic number.

It is an amenable number.

31123313 is a deficient number, since it is larger than the sum of its proper divisors (2394115).

31123313 is a wasteful number, since it uses less digits than its factorization.

31123313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2394114.

The product of its digits is 162, while the sum is 17.

The square root of 31123313 is about 5578.8272065014. The cubic root of 31123313 is about 314.5540443452.

Adding to 31123313 its reverse (31332113), we get a palindrome (62455426).

The spelling of 31123313 in words is "thirty-one million, one hundred twenty-three thousand, three hundred thirteen".