1666100 has 18 divisors (see below), whose sum is σ = 3615654. Its totient is φ = 666400.

The previous prime is 1666081. The next prime is 1666111. The reversal of 1666100 is 16661.

It can be written as a sum of positive squares in 3 ways, for example, as 98596 + 1567504 = 314^2 + 1252^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 8231 + ... + 8430.

2^1666100 is an apocalyptic number.

1666100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1666100 is an abundant number, since it is smaller than the sum of its proper divisors (1949554).

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

1666100 is a wasteful number, since it uses less digits than its factorization.

1666100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16675 (or 16668 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 1666100 is about 1290.7749610215. The cubic root of 1666100 is about 118.5496714740.

Multiplying 1666100 by its reverse (16661), we get a square (27758892100 = 166610²).

1666100 divided by its reverse (16661) gives a square (100 = 10²).

The spelling of 1666100 in words is "one million, six hundred sixty-six thousand, one hundred".