6640228 has 12 divisors (see below), whose sum is σ = 13280512. Its totient is φ = 2845800.

The previous prime is 6640223. The next prime is 6640241. The reversal of 6640228 is 8220466.

6640228 is an admirable number.

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (28), and also a Moran number because the ratio is a prime number: 237151 = 6640228 / (6 + 6 + 4 + 0 + 2 + 2 + 8).

It is a junction number, because it is equal to n+sod(n) for n = 6640196 and 6640205.

It is not an unprimeable number, because it can be changed into a prime (6640223) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 118548 + ... + 118603.

Almost surely, 2^6640228 is an apocalyptic number.

It is an amenable number.

6640228 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.

6640228 is a wasteful number, since it uses less digits than its factorization.

6640228 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 237162 (or 237160 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 28.

The square root of 6640228 is about 2576.8639855452. The cubic root of 6640228 is about 187.9580787772.

It can be divided in two parts, 66402 and 28, that added together give a triangular number (66430 = T₃₆₄).

The spelling of 6640228 in words is "six million, six hundred forty thousand, two hundred twenty-eight".