1666000 has 120 divisors (see below), whose sum is σ = 4961736. Its totient is φ = 537600.

The previous prime is 1665997. The next prime is 1666003. The reversal of 1666000 is 6661.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1665997) and next prime (1666003).

It can be written as a sum of positive squares in 4 ways, for example, as 7056 + 1658944 = 84^2 + 1288^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666003) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 97992 + ... + 98008.

2^1666000 is an apocalyptic number.

1666000 is a gapful number since it is divisible by the number (10) 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 1666000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2480868).

1666000 is an abundant number, since it is smaller than the sum of its proper divisors (3295736).

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

1666000 is a wasteful number, since it uses less digits than its factorization.

1666000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54 (or 31 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 19.

The square root of 1666000 is about 1290.7362240210. The cubic root of 1666000 is about 118.5472996267.

The spelling of 1666000 in words is "one million, six hundred sixty-six thousand".