6643218 has 8 divisors (see below), whose sum is σ = 13286448. Its totient is φ = 2214404.

The previous prime is 6643213. The next prime is 6643229. The reversal of 6643218 is 8123466.

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

6643218 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (6643211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 553596 + ... + 553607.

It is an arithmetic number, because the mean of its divisors is an integer number (1660806).

Almost surely, 2^6643218 is an apocalyptic number.

6643218 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

6643218 is a wasteful number, since it uses less digits than its factorization.

6643218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1107208.

The product of its digits is 6912, while the sum is 30.

The square root of 6643218 is about 2577.4440828076. Note that the first 3 decimals coincide. The cubic root of 6643218 is about 187.9862861582.

The spelling of 6643218 in words is "six million, six hundred forty-three thousand, two hundred eighteen".