6663399 has 16 divisors (see below), whose sum is σ = 9331200. Its totient is φ = 4221536.

The previous prime is 6663389. The next prime is 6663407. The reversal of 6663399 is 9933666.

It is a cyclic number.

It is not a de Polignac number, because 6663399 - 2⁴ = 6663383 is a prime.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a zygodrome in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 6663399.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6663329) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18382 + ... + 18740.

It is an arithmetic number, because the mean of its divisors is an integer number (583200).

Almost surely, 2^6663399 is an apocalyptic number.

6663399 is a gapful number since it is divisible by the number (69) formed by its first and last digit.

6663399 is a deficient number, since it is larger than the sum of its proper divisors (2667801).

6663399 is a wasteful number, since it uses less digits than its factorization.

6663399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 654.

The product of its digits is 157464, while the sum is 42.

The square root of 6663399 is about 2581.3560389842. The cubic root of 6663399 is about 188.1764508302.

The spelling of 6663399 in words is "six million, six hundred sixty-three thousand, three hundred ninety-nine".