666810 has 48 divisors (see below), whose sum is σ = 1797120. Its totient is φ = 171360.

The previous prime is 666773. The next prime is 666811. The reversal of 666810 is 18666.

666810 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×666810² = 889271152200, which contains 22 as substring.

It is a Curzon 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 23 ways as a sum of consecutive naturals, for example, 2671 + ... + 2909.

It is an arithmetic number, because the mean of its divisors is an integer number (37440).

2⁶⁶⁶⁸¹⁰ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 666810, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (898560).

666810 is an abundant number, since it is smaller than the sum of its proper divisors (1130310).

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

666810 is a wasteful number, since it uses less digits than its factorization.

666810 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 283 (or 280 counting only the distinct ones).

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

The square root of 666810 is about 816.5843495929. The cubic root of 666810 is about 87.3643066850.

The spelling of 666810 in words is "six hundred sixty-six thousand, eight hundred ten".