31663913 has 2 divisors, whose sum is σ = 31663914. Its totient is φ = 31663912.

The previous prime is 31663909. The next prime is 31663921. The reversal of 31663913 is 31936613.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 31663129 + 784 = 5627^2 + 28^2 .

It is an emirp because it is prime and its reverse (31936613) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31663913 - 2² = 31663909 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 31663913.

It is not a weakly prime, because it can be changed into another prime (31663963) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15831956 + 15831957.

It is an arithmetic number, because the mean of its divisors is an integer number (15831957).

Almost surely, 2^31663913 is an apocalyptic number.

It is an amenable number.

31663913 is a deficient number, since it is larger than the sum of its proper divisors (1).

31663913 is an equidigital number, since it uses as much as digits as its factorization.

31663913 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8748, while the sum is 32.

The square root of 31663913 is about 5627.0696636882. The cubic root of 31663913 is about 316.3648279295.

The spelling of 31663913 in words is "thirty-one million, six hundred sixty-three thousand, nine hundred thirteen".