31312111 has 4 divisors (see below), whose sum is σ = 31423824. Its totient is φ = 31200400.

The previous prime is 31312097. The next prime is 31312117. The reversal of 31312111 is 11121313.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 11121313 = 7 ⋅1588759.

It is a cyclic number.

It is not a de Polignac number, because 31312111 - 2⁷ = 31311983 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31312091 and 31312100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31312117) 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 in 3 ways as a sum of consecutive naturals, for example, 55435 + ... + 55996.

It is an arithmetic number, because the mean of its divisors is an integer number (7855956).

Almost surely, 2^31312111 is an apocalyptic number.

31312111 is a deficient number, since it is larger than the sum of its proper divisors (111713).

31312111 is a wasteful number, since it uses less digits than its factorization.

31312111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111712.

The product of its digits is 18, while the sum is 13.

The square root of 31312111 is about 5595.7225628153. The cubic root of 31312111 is about 315.1888042557.

Adding to 31312111 its reverse (11121313), we get a palindrome (42433424).

The spelling of 31312111 in words is "thirty-one million, three hundred twelve thousand, one hundred eleven".