39664646689 has 2 divisors, whose sum is σ = 39664646690. Its totient is φ = 39664646688.

The previous prime is 39664646663. The next prime is 39664646701. The reversal of 39664646689 is 98664646693.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 39597816064 + 66830625 = 198992^2 + 8175^2 .

It is a cyclic number.

It is not a de Polignac number, because 39664646689 - 2⁵ = 39664646657 is a prime.

It is not a weakly prime, because it can be changed into another prime (39664644689) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19832323344 + 19832323345.

It is an arithmetic number, because the mean of its divisors is an integer number (19832323345).

Almost surely, 2^39664646689 is an apocalyptic number.

It is an amenable number.

39664646689 is a deficient number, since it is larger than the sum of its proper divisors (1).

39664646689 is an equidigital number, since it uses as much as digits as its factorization.

39664646689 is an evil number, because the sum of its binary digits is even.

The product of its digits is 241864704, while the sum is 67.

The spelling of 39664646689 in words is "thirty-nine billion, six hundred sixty-four million, six hundred forty-six thousand, six hundred eighty-nine".