6643869 has 4 divisors (see below), whose sum is σ = 8858496. Its totient is φ = 4429244.

The previous prime is 6643859. The next prime is 6643883. The reversal of 6643869 is 9683466.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 6643869 - 2⁵ = 6643837 is a prime.

It is a super-2 number, since 2×6643869² = 88281990578322, which contains 22 as substring.

It is a D-number.

It is a self number, because there is not a number n which added to its sum of digits gives 6643869.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6643829) 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, 1107309 + ... + 1107314.

It is an arithmetic number, because the mean of its divisors is an integer number (2214624).

Almost surely, 2^6643869 is an apocalyptic number.

It is an amenable number.

6643869 is a deficient number, since it is larger than the sum of its proper divisors (2214627).

6643869 is a wasteful number, since it uses less digits than its factorization.

6643869 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2214626.

The product of its digits is 186624, while the sum is 42.

The square root of 6643869 is about 2577.5703676137. The cubic root of 6643869 is about 187.9924265095.

The spelling of 6643869 in words is "six million, six hundred forty-three thousand, eight hundred sixty-nine".