31318031 has 2 divisors, whose sum is σ = 31318032. Its totient is φ = 31318030.

The previous prime is 31318013. The next prime is 31318033. The reversal of 31318031 is 13081313.

It is a happy number.

Together with previous prime (31318013) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 31318031 - 2²² = 27123727 is a prime.

It is a super-2 number, since 2×31318031² = 1961638131433922, which contains 22 as substring.

Together with 31318033, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 31317994 and 31318012.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31318033) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15659015 + 15659016.

It is an arithmetic number, because the mean of its divisors is an integer number (15659016).

Almost surely, 2^31318031 is an apocalyptic number.

31318031 is a deficient number, since it is larger than the sum of its proper divisors (1).

31318031 is an equidigital number, since it uses as much as digits as its factorization.

31318031 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 31318031 is about 5596.2515132899. The cubic root of 31318031 is about 315.2086666463.

Adding to 31318031 its reverse (13081313), we get a palindrome (44399344).

The spelling of 31318031 in words is "thirty-one million, three hundred eighteen thousand, thirty-one".