6643779 has 8 divisors (see below), whose sum is σ = 9047040. Its totient is φ = 4334856.

The previous prime is 6643739. The next prime is 6643781. The reversal of 6643779 is 9773466.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-6643779 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 6643779.

It is not an unprimeable number, because it can be changed into a prime (6643729) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23419 + ... + 23700.

It is an arithmetic number, because the mean of its divisors is an integer number (1130880).

Almost surely, 2^6643779 is an apocalyptic number.

6643779 is a deficient number, since it is larger than the sum of its proper divisors (2403261).

6643779 is a wasteful number, since it uses less digits than its factorization.

6643779 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47169.

The product of its digits is 190512, while the sum is 42.

The square root of 6643779 is about 2577.5529092533. The cubic root of 6643779 is about 187.9915776369.

The spelling of 6643779 in words is "six million, six hundred forty-three thousand, seven hundred seventy-nine".