31996691 has 2 divisors, whose sum is σ = 31996692. Its totient is φ = 31996690.

The previous prime is 31996663. The next prime is 31996693. The reversal of 31996691 is 19669913.

It is a happy number.

It is a strong prime.

It is an emirp because it is prime and its reverse (19669913) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31996691 - 2¹⁴ = 31980307 is a prime.

Together with 31996693, 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 (31996693) 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, 15998345 + 15998346.

It is an arithmetic number, because the mean of its divisors is an integer number (15998346).

Almost surely, 2^31996691 is an apocalyptic number.

31996691 is a deficient number, since it is larger than the sum of its proper divisors (1).

31996691 is an equidigital number, since it uses as much as digits as its factorization.

31996691 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 78732, while the sum is 44.

The square root of 31996691 is about 5656.5617648886. The cubic root of 31996691 is about 317.4692668704.

The spelling of 31996691 in words is "thirty-one million, nine hundred ninety-six thousand, six hundred ninety-one".