39985659691 has 2 divisors, whose sum is σ = 39985659692. Its totient is φ = 39985659690.

The previous prime is 39985659671. The next prime is 39985659731. The reversal of 39985659691 is 19695658993.

It is a weak prime.

It is an emirp because it is prime and its reverse (19695658993) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 39985659691 - 2⁹ = 39985659179 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 39985659691.

It is not a weakly prime, because it can be changed into another prime (39985659671) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19992829845 + 19992829846.

It is an arithmetic number, because the mean of its divisors is an integer number (19992829846).

Almost surely, 2^39985659691 is an apocalyptic number.

39985659691 is a deficient number, since it is larger than the sum of its proper divisors (1).

39985659691 is an equidigital number, since it uses as much as digits as its factorization.

39985659691 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 141717600, while the sum is 70.

The spelling of 39985659691 in words is "thirty-nine billion, nine hundred eighty-five million, six hundred fifty-nine thousand, six hundred ninety-one".