12678666 has 64 divisors (see below), whose sum is σ = 34062336. Its totient is φ = 3038400.

The previous prime is 12678661. The next prime is 12678671. The reversal of 12678666 is 66687621.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (12678661) and next prime (12678671).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (12678661) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4951 + ... + 7061.

It is an arithmetic number, because the mean of its divisors is an integer number (532224).

Almost surely, 2^12678666 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 12678666, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (17031168).

12678666 is an abundant number, since it is smaller than the sum of its proper divisors (21383670).

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

12678666 is a wasteful number, since it uses less digits than its factorization.

12678666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2147.

The product of its digits is 145152, while the sum is 42.

The square root of 12678666 is about 3560.7114457647. The cubic root of 12678666 is about 233.1799404518.

The spelling of 12678666 in words is "twelve million, six hundred seventy-eight thousand, six hundred sixty-six".