801666 has 12 divisors (see below), whose sum is σ = 1736982. Its totient is φ = 267216.

The previous prime is 801641. The next prime is 801677. The reversal of 801666 is 666108.

It can be written as a sum of positive squares in only one way, i.e., 416025 + 385641 = 645^2 + 621^2 .

It is a Curzon number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 801666.

It is an unprimeable number.

801666 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 22251 + ... + 22286.

2⁸⁰¹⁶⁶⁶ is an apocalyptic number.

801666 is an abundant number, since it is smaller than the sum of its proper divisors (935316).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

801666 is a wasteful number, since it uses less digits than its factorization.

801666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44545 (or 44542 counting only the distinct ones).

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

The square root of 801666 is about 895.3580289471. The cubic root of 801666 is about 92.8961727163.

The spelling of 801666 in words is "eight hundred one thousand, six hundred sixty-six".