6665779 has 4 divisors (see below), whose sum is σ = 6728184. Its totient is φ = 6603376.

The previous prime is 6665777. The next prime is 6665797. The reversal of 6665779 is 9775666.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9775666 = 2 ⋅4887833.

It is a cyclic number.

It is not a de Polignac number, because 6665779 - 2¹ = 6665777 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6665773) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31042 + ... + 31255.

It is an arithmetic number, because the mean of its divisors is an integer number (1682046).

Almost surely, 2^6665779 is an apocalyptic number.

6665779 is a deficient number, since it is larger than the sum of its proper divisors (62405).

6665779 is a wasteful number, since it uses less digits than its factorization.

6665779 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62404.

The product of its digits is 476280, while the sum is 46.

The square root of 6665779 is about 2581.8169958384. The cubic root of 6665779 is about 188.1988521423.

The spelling of 6665779 in words is "six million, six hundred sixty-five thousand, seven hundred seventy-nine".