6639606859 has 4 divisors (see below), whose sum is σ = 6652302616. Its totient is φ = 6626911104.

The previous prime is 6639606817. The next prime is 6639606881. The reversal of 6639606859 is 9586069366.

It is a happy number.

6639606859 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6639606859 is a prime.

It is a super-3 number, since 3×6639606859³ (a number of 30 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6639606889) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6347094 + ... + 6348139.

It is an arithmetic number, because the mean of its divisors is an integer number (1663075654).

Almost surely, 2^6639606859 is an apocalyptic number.

6639606859 is a deficient number, since it is larger than the sum of its proper divisors (12695757).

6639606859 is a wasteful number, since it uses less digits than its factorization.

6639606859 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12695756.

The product of its (nonzero) digits is 12597120, while the sum is 58.

The square root of 6639606859 is about 81483.7827975604. The cubic root of 6639606859 is about 1879.5221792879.

The spelling of 6639606859 in words is "six billion, six hundred thirty-nine million, six hundred six thousand, eight hundred fifty-nine".