6639965 has 8 divisors (see below), whose sum is σ = 7983360. Its totient is φ = 5301712.

The previous prime is 6639943. The next prime is 6639989. The reversal of 6639965 is 5699366.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 6639965 - 2¹⁴ = 6623581 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2672 + ... + 4518.

It is an arithmetic number, because the mean of its divisors is an integer number (997920).

Almost surely, 2^6639965 is an apocalyptic number.

It is an amenable number.

6639965 is a deficient number, since it is larger than the sum of its proper divisors (1343395).

6639965 is a wasteful number, since it uses less digits than its factorization.

6639965 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2571.

The product of its digits is 262440, while the sum is 44.

The square root of 6639965 is about 2576.8129540190. The cubic root of 6639965 is about 187.9555972546.

The spelling of 6639965 in words is "six million, six hundred thirty-nine thousand, nine hundred sixty-five".