666000 has 120 divisors (see below), whose sum is σ = 2388984. Its totient is φ = 172800.

The previous prime is 665993. The next prime is 666013. The reversal of 666000 is 666.

It can be written as a sum of positive squares in 4 ways, for example, as 144 + 665856 = 12^2 + 816^2 .

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.

It is a nialpdrome in base 10.

It is a zygodrome in base 10.

It is an unprimeable number.

666000 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 17982 + ... + 18018.

2⁶⁶⁶⁰⁰⁰ is an apocalyptic number.

666000 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 666000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1194492).

666000 is an abundant number, since it is smaller than the sum of its proper divisors (1722984).

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

666000 is a wasteful number, since it uses less digits than its factorization.

666000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66 (or 47 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

The square root of 666000 is about 816.0882305241. The cubic root of 666000 is about 87.3289174130.

Adding to 666000 its reverse (666), we get a palindrome (666666).

666000 divided by its reverse (666) gives a cube (1000 = 10³).

The spelling of 666000 in words is "six hundred sixty-six thousand".