6647979 has 16 divisors (see below), whose sum is σ = 9592352. Its totient is φ = 4071168.

The previous prime is 6647959. The next prime is 6647983. The reversal of 6647979 is 9797466.

It is not a de Polignac number, because 6647979 - 2⁵ = 6647947 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6647909) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14319 + ... + 14775.

It is an arithmetic number, because the mean of its divisors is an integer number (599522).

Almost surely, 2^6647979 is an apocalyptic number.

6647979 is a deficient number, since it is larger than the sum of its proper divisors (2944373).

6647979 is a wasteful number, since it uses less digits than its factorization.

6647979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 846.

The product of its digits is 571536, while the sum is 48.

The square root of 6647979 is about 2578.3675067763. The cubic root of 6647979 is about 188.0311835251.

It can be divided in two parts, 6647 and 979, that added together give a triangular number (7626 = T₁₂₃).

The spelling of 6647979 in words is "six million, six hundred forty-seven thousand, nine hundred seventy-nine".