1666564 has 12 divisors (see below), whose sum is σ = 2926924. Its totient is φ = 830304.

The previous prime is 1666559. The next prime is 1666589. The reversal of 1666564 is 4656661.

It can be written as a sum of positive squares in 2 ways, for example, as 412164 + 1254400 = 642^2 + 1120^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 934 + ... + 2050.

2^1666564 is an apocalyptic number.

It is an amenable number.

1666564 is a deficient number, since it is larger than the sum of its proper divisors (1260360).

1666564 is a wasteful number, since it uses less digits than its factorization.

1666564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1494 (or 1492 counting only the distinct ones).

The product of its digits is 25920, while the sum is 34.

The square root of 1666564 is about 1290.9546854944. The cubic root of 1666564 is about 118.5606756038.

It can be divided in two parts, 16 and 66564, that multiplied together give a square (1065024 = 1032²).

The spelling of 1666564 in words is "one million, six hundred sixty-six thousand, five hundred sixty-four".