666747 has 12 divisors (see below), whose sum is σ = 1005264. Its totient is φ = 425040.

The previous prime is 666737. The next prime is 666749. The reversal of 666747 is 747666.

It is not a de Polignac number, because 666747 - 2⁶ = 666683 is a prime.

It is not an unprimeable number, because it can be changed into a prime (666749) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1404 + ... + 1817.

It is an arithmetic number, because the mean of its divisors is an integer number (83772).

2⁶⁶⁶⁷⁴⁷ is an apocalyptic number.

666747 is a deficient number, since it is larger than the sum of its proper divisors (338517).

666747 is a wasteful number, since it uses less digits than its factorization.

666747 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3250 (or 3247 counting only the distinct ones).

The product of its digits is 42336, while the sum is 36.

The square root of 666747 is about 816.5457733648. The cubic root of 666747 is about 87.3615552142.

The spelling of 666747 in words is "six hundred sixty-six thousand, seven hundred forty-seven".