6668218 has 4 divisors (see below), whose sum is σ = 10002330. Its totient is φ = 3334108.

The previous prime is 6668213. The next prime is 6668237. The reversal of 6668218 is 8128666.

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

It can be written as a sum of positive squares in only one way, i.e., 6335289 + 332929 = 2517^2 + 577^2 .

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (6668213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1667053 + ... + 1667056.

Almost surely, 2^6668218 is an apocalyptic number.

6668218 is a deficient number, since it is larger than the sum of its proper divisors (3334112).

6668218 is a wasteful number, since it uses less digits than its factorization.

6668218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3334111.

The product of its digits is 27648, while the sum is 37.

The square root of 6668218 is about 2582.2892944053. The cubic root of 6668218 is about 188.2218032496.

It can be divided in two parts, 6668 and 218, that added together give a palindrome (6886).

The spelling of 6668218 in words is "six million, six hundred sixty-eight thousand, two hundred eighteen".