65639640663 has 12 divisors (see below), whose sum is σ = 96367123528. Its totient is φ = 43042386960.

The previous prime is 65639640641. The next prime is 65639640667. The reversal of 65639640663 is 36604693656.

It is a happy number.

It is not a de Polignac number, because 65639640663 - 2²⁶ = 65572531799 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65639640667) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 59780545 + ... + 59781642.

Almost surely, 2^65639640663 is an apocalyptic number.

65639640663 is a deficient number, since it is larger than the sum of its proper divisors (30727482865).

65639640663 is a wasteful number, since it uses less digits than its factorization.

65639640663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 119562254 (or 119562251 counting only the distinct ones).

The product of its (nonzero) digits is 12597120, while the sum is 54.

The spelling of 65639640663 in words is "sixty-five billion, six hundred thirty-nine million, six hundred forty thousand, six hundred sixty-three".