6643828 has 6 divisors (see below), whose sum is σ = 11626706. Its totient is φ = 3321912.

The previous prime is 6643823. The next prime is 6643829. The reversal of 6643828 is 8283466.

It can be written as a sum of positive squares in only one way, i.e., 5438224 + 1205604 = 2332^2 + 1098^2 .

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6643823) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 830475 + ... + 830482.

Almost surely, 2^6643828 is an apocalyptic number.

It is an amenable number.

6643828 is a deficient number, since it is larger than the sum of its proper divisors (4982878).

6643828 is a wasteful number, since it uses less digits than its factorization.

6643828 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1660961 (or 1660959 counting only the distinct ones).

The product of its digits is 55296, while the sum is 37.

The square root of 6643828 is about 2577.5624143753. The cubic root of 6643828 is about 187.9920398018.

It can be divided in two parts, 66438 and 28, that added together give a palindrome (66466).

The spelling of 6643828 in words is "six million, six hundred forty-three thousand, eight hundred twenty-eight".