31315937 has 2 divisors, whose sum is σ = 31315938. Its totient is φ = 31315936.

The previous prime is 31315927. The next prime is 31315939. The reversal of 31315937 is 73951313.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19749136 + 11566801 = 4444^2 + 3401^2 .

It is an emirp because it is prime and its reverse (73951313) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31315937 is a prime.

Together with 31315939, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (31315939) 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 as a sum of consecutive naturals, namely, 15657968 + 15657969.

It is an arithmetic number, because the mean of its divisors is an integer number (15657969).

Almost surely, 2^31315937 is an apocalyptic number.

It is an amenable number.

31315937 is a deficient number, since it is larger than the sum of its proper divisors (1).

31315937 is an equidigital number, since it uses as much as digits as its factorization.

31315937 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8505, while the sum is 32.

The square root of 31315937 is about 5596.0644206442. The cubic root of 31315937 is about 315.2016412828.

The spelling of 31315937 in words is "thirty-one million, three hundred fifteen thousand, nine hundred thirty-seven".