6663993666 has 32 divisors (see below), whose sum is σ = 14599987776. Its totient is φ = 2011008000.

The previous prime is 6663993649. The next prime is 6663993673.

6663993666 is nontrivially palindromic in base 10.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 193575 + ... + 225386.

It is an arithmetic number, because the mean of its divisors is an integer number (456249618).

Almost surely, 2^6663993666 is an apocalyptic number.

6663993666 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

6663993666 is an abundant number, since it is smaller than the sum of its proper divisors (7935994110).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6663993666 is a wasteful number, since it uses less digits than its factorization.

6663993666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 419218.

The product of its digits is 34012224, while the sum is 60.

The square root of 6663993666 is about 81633.2877323950. The cubic root of 6663993666 is about 1881.8204851431.

The spelling of 6663993666 in words is "six billion, six hundred sixty-three million, nine hundred ninety-three thousand, six hundred sixty-six".