12561666 has 16 divisors (see below), whose sum is σ = 27056064. Its totient is φ = 3865104.

The previous prime is 12561599. The next prime is 12561671. The reversal of 12561666 is 66616521.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 80446 + ... + 80601.

It is an arithmetic number, because the mean of its divisors is an integer number (1691004).

Almost surely, 2^12561666 is an apocalyptic number.

12561666 is an abundant number, since it is smaller than the sum of its proper divisors (14494398).

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

12561666 is a wasteful number, since it uses less digits than its factorization.

12561666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 161065.

The product of its digits is 12960, while the sum is 33.

The square root of 12561666 is about 3544.2440660880. The cubic root of 12561666 is about 232.4604534426.

The spelling of 12561666 in words is "twelve million, five hundred sixty-one thousand, six hundred sixty-six".