6643636 has 12 divisors (see below), whose sum is σ = 11823840. Its totient is φ = 3265400.

The previous prime is 6643633. The next prime is 6643649. The reversal of 6643636 is 6363466.

It is a d-powerful number, because it can be written as 6⁴ + 6⁴ + 4² + 3¹¹ + 6⁴ + 3¹⁴ + 6⁸ .

6643636 is a modest number, since divided by 3636 gives 664 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6643633) 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, 13840 + ... + 14311.

It is an arithmetic number, because the mean of its divisors is an integer number (985320).

Almost surely, 2^6643636 is an apocalyptic number.

It is an amenable number.

6643636 is a deficient number, since it is larger than the sum of its proper divisors (5180204).

6643636 is a wasteful number, since it uses less digits than its factorization.

6643636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28214 (or 28212 counting only the distinct ones).

The product of its digits is 46656, while the sum is 34.

The square root of 6643636 is about 2577.5251696152. The cubic root of 6643636 is about 187.9902288569.

The spelling of 6643636 in words is "six million, six hundred forty-three thousand, six hundred thirty-six".