6664665 has 16 divisors (see below), whose sum is σ = 12187008. Its totient is φ = 3046656.

The previous prime is 6664661. The next prime is 6664667. The reversal of 6664665 is 5664666.

It is not a de Polignac number, because 6664665 - 2² = 6664661 is a prime.

It is not an unprimeable number, because it can be changed into a prime (6664661) 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 15 ways as a sum of consecutive naturals, for example, 31632 + ... + 31841.

It is an arithmetic number, because the mean of its divisors is an integer number (761688).

Almost surely, 2^6664665 is an apocalyptic number.

It is an amenable number.

6664665 is a deficient number, since it is larger than the sum of its proper divisors (5522343).

6664665 is a wasteful number, since it uses less digits than its factorization.

6664665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63488.

The product of its digits is 155520, while the sum is 39.

The square root of 6664665 is about 2581.6012472882. The cubic root of 6664665 is about 188.1883674862.

Subtracting from 6664665 its reverse (5664666), we obtain a palindrome (999999).

The spelling of 6664665 in words is "six million, six hundred sixty-four thousand, six hundred sixty-five".