666801 has 12 divisors (see below), whose sum is σ = 986128. Its totient is φ = 433944.

The previous prime is 666773. The next prime is 666811. The reversal of 666801 is 108666.

It is not a de Polignac number, because 666801 - 2⁵ = 666769 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (666811) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 475 + ... + 1248.

2⁶⁶⁶⁸⁰¹ is an apocalyptic number.

It is an amenable number.

666801 is a deficient number, since it is larger than the sum of its proper divisors (319327).

666801 is a wasteful number, since it uses less digits than its factorization.

666801 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1772 (or 1769 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 666801 is about 816.5788388147. The cubic root of 666801 is about 87.3639136284.

The spelling of 666801 in words is "six hundred sixty-six thousand, eight hundred one".