1666600 has 48 divisors (see below), whose sum is σ = 4179420. Its totient is φ = 614400.

The previous prime is 1666597. The next prime is 1666607. The reversal of 1666600 is 66661.

It can be written as a sum of positive squares in 6 ways, for example, as 662596 + 1004004 = 814^2 + 1002^2 .

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666607) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2280 + ... + 2920.

2^1666600 is an apocalyptic number.

1666600 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 1666600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2089710).

1666600 is an abundant number, since it is smaller than the sum of its proper divisors (2512820).

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

1666600 is a wasteful number, since it uses less digits than its factorization.

1666600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 670 (or 661 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 25.

The square root of 1666600 is about 1290.9686285886. The cubic root of 1666600 is about 118.5615292871.

The spelling of 1666600 in words is "one million, six hundred sixty-six thousand, six hundred".