1800666 has 48 divisors (see below), whose sum is σ = 4612608. Its totient is φ = 496800.

The previous prime is 1800641. The next prime is 1800677. The reversal of 1800666 is 6660081.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3676 + ... + 4136.

It is an arithmetic number, because the mean of its divisors is an integer number (96096).

2^1800666 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1800666, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2306304).

1800666 is an abundant number, since it is smaller than the sum of its proper divisors (2811942).

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

1800666 is a wasteful number, since it uses less digits than its factorization.

1800666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 507 (or 504 counting only the distinct ones).

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

The square root of 1800666 is about 1341.8889670908. Note that the first 3 decimals coincide. The cubic root of 1800666 is about 121.6590408264.

The spelling of 1800666 in words is "one million, eight hundred thousand, six hundred sixty-six".