6645667 has 4 divisors (see below), whose sum is σ = 7595056. Its totient is φ = 5696280.

The previous prime is 6645641. The next prime is 6645677. The reversal of 6645667 is 7665466.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6645667 is a prime.

It is not an unprimeable number, because it can be changed into a prime (6645637) 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, 474684 + ... + 474697.

It is an arithmetic number, because the mean of its divisors is an integer number (1898764).

Almost surely, 2^6645667 is an apocalyptic number.

6645667 is a deficient number, since it is larger than the sum of its proper divisors (949389).

6645667 is an equidigital number, since it uses as much as digits as its factorization.

6645667 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 949388.

The product of its digits is 181440, while the sum is 40.

The square root of 6645667 is about 2577.9191220828. The cubic root of 6645667 is about 188.0093834912.

The spelling of 6645667 in words is "six million, six hundred forty-five thousand, six hundred sixty-seven".