12966561 has 10 divisors (see below), whose sum is σ = 19369922. Its totient is φ = 8644320.

The previous prime is 12966559. The next prime is 12966589. The reversal of 12966561 is 16566921.

12966561 is a `hidden beast` number, since 1 + 2 + 96 + 6 + 561 = 666.

12966561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 12960000 + 6561 = 3600^2 + 81^2 .

It is not a de Polignac number, because 12966561 - 2¹ = 12966559 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (12966661) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 79960 + ... + 80121.

Almost surely, 2^12966561 is an apocalyptic number.

It is an amenable number.

12966561 is a deficient number, since it is larger than the sum of its proper divisors (6403361).

12966561 is an equidigital number, since it uses as much as digits as its factorization.

12966561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160093 (or 160084 counting only the distinct ones).

The product of its digits is 19440, while the sum is 36.

The square root of 12966561 is about 3600.9111346991. The cubic root of 12966561 is about 234.9316898180.

It can be divided in two parts, 1296 and 6561, that multiplied together give a 4-th power (8503056 = 54⁴).

The spelling of 12966561 in words is "twelve million, nine hundred sixty-six thousand, five hundred sixty-one".