666949673 has 8 divisors (see below), whose sum is σ = 718878216. Its totient is φ = 615110400.

The previous prime is 666949667. The next prime is 666949687. The reversal of 666949673 is 376949666.

It can be written as a sum of positive squares in 4 ways, for example, as 81938704 + 585010969 = 9052^2 + 24187^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 666949673 - 2¹⁰ = 666948649 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (666949643) 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 7 ways as a sum of consecutive naturals, for example, 6368 + ... + 37073.

It is an arithmetic number, because the mean of its divisors is an integer number (89859777).

Almost surely, 2^666949673 is an apocalyptic number.

It is an amenable number.

666949673 is a deficient number, since it is larger than the sum of its proper divisors (51928543).

666949673 is a wasteful number, since it uses less digits than its factorization.

666949673 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44635.

The product of its digits is 8817984, while the sum is 56.

The square root of 666949673 is about 25825.3687872990. The cubic root of 666949673 is about 873.7040616507.

It can be divided in two parts, 66694 and 9673, that added together give a palindrome (76367).

The spelling of 666949673 in words is "six hundred sixty-six million, nine hundred forty-nine thousand, six hundred seventy-three".