39643687697 has 2 divisors, whose sum is σ = 39643687698. Its totient is φ = 39643687696.

The previous prime is 39643687687. The next prime is 39643687717. The reversal of 39643687697 is 79678634693.

39643687697 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 30490747456 + 9152940241 = 174616^2 + 95671^2 .

It is a cyclic number.

It is not a de Polignac number, because 39643687697 - 2¹⁴ = 39643671313 is a prime.

It is not a weakly prime, because it can be changed into another prime (39643687607) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19821843848 + 19821843849.

It is an arithmetic number, because the mean of its divisors is an integer number (19821843849).

Almost surely, 2^39643687697 is an apocalyptic number.

It is an amenable number.

39643687697 is a deficient number, since it is larger than the sum of its proper divisors (1).

39643687697 is an equidigital number, since it uses as much as digits as its factorization.

39643687697 is an evil number, because the sum of its binary digits is even.

The product of its digits is 246903552, while the sum is 68.

The spelling of 39643687697 in words is "thirty-nine billion, six hundred forty-three million, six hundred eighty-seven thousand, six hundred ninety-seven".