1666660 has 24 divisors (see below), whose sum is σ = 3528000. Its totient is φ = 661344.

The previous prime is 1666657. The next prime is 1666711. The reversal of 1666660 is 666661.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 3091 + ... + 3589.

It is an arithmetic number, because the mean of its divisors is an integer number (147000).

2^1666660 is an apocalyptic number.

1666660 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1666660 is an abundant number, since it is smaller than the sum of its proper divisors (1861340).

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

1666660 is a wasteful number, since it uses less digits than its factorization.

1666660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 675 (or 673 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 31.

The square root of 1666660 is about 1290.9918667443. The cubic root of 1666660 is about 118.5629520653.

Adding to 1666660 its product of nonzero digits (7776), we get a square (1674436 = 1294²).

Subtracting from 1666660 its reverse (666661), we obtain a palindrome (999999).

The spelling of 1666660 in words is "one million, six hundred sixty-six thousand, six hundred sixty".