12400666 has 4 divisors (see below), whose sum is σ = 18601002. Its totient is φ = 6200332.

The previous prime is 12400643. The next prime is 12400669. The reversal of 12400666 is 66600421.

It is a happy number.

12400666 is nontrivially palindromic in base 15.

12400666 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 66600421 = 43 ⋅1548847.

It can be written as a sum of positive squares in only one way, i.e., 7868025 + 4532641 = 2805^2 + 2129^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 12400666.

It is not an unprimeable number, because it can be changed into a prime (12400669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3100165 + ... + 3100168.

Almost surely, 2^12400666 is an apocalyptic number.

12400666 is a deficient number, since it is larger than the sum of its proper divisors (6200336).

12400666 is an equidigital number, since it uses as much as digits as its factorization.

12400666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6200335.

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 12400666 is about 3521.4579367075. The cubic root of 12400666 is about 231.4630492395.

The spelling of 12400666 in words is "twelve million, four hundred thousand, six hundred sixty-six".