31608131 has 2 divisors, whose sum is σ = 31608132. Its totient is φ = 31608130.

The previous prime is 31608107. The next prime is 31608133. The reversal of 31608131 is 13180613.

It is a strong prime.

It is an emirp because it is prime and its reverse (13180613) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31608131 - 2⁶ = 31608067 is a prime.

It is a super-2 number, since 2×31608131² = 1998147890626322, which contains 22 as substring.

Together with 31608133, 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 = 31608097 and 31608106.

It is not a weakly prime, because it can be changed into another prime (31608133) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15804065 + 15804066.

It is an arithmetic number, because the mean of its divisors is an integer number (15804066).

Almost surely, 2^31608131 is an apocalyptic number.

31608131 is a deficient number, since it is larger than the sum of its proper divisors (1).

31608131 is an equidigital number, since it uses as much as digits as its factorization.

31608131 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 31608131 is about 5622.1109024992. The cubic root of 31608131 is about 316.1789398061.

Adding to 31608131 its reverse (13180613), we get a palindrome (44788744).

The spelling of 31608131 in words is "thirty-one million, six hundred eight thousand, one hundred thirty-one".