12678661 has 2 divisors, whose sum is σ = 12678662. Its totient is φ = 12678660.

The previous prime is 12678649. The next prime is 12678671. The reversal of 12678661 is 16687621.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11902500 + 776161 = 3450^2 + 881^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12678661 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 12678661.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12678671) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6339330 + 6339331.

It is an arithmetic number, because the mean of its divisors is an integer number (6339331).

Almost surely, 2^12678661 is an apocalyptic number.

It is an amenable number.

12678661 is a deficient number, since it is larger than the sum of its proper divisors (1).

12678661 is an equidigital number, since it uses as much as digits as its factorization.

12678661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 24192, while the sum is 37.

The square root of 12678661 is about 3560.7107436578. The cubic root of 12678661 is about 233.1799097992.

It can be divided in two parts, 126 and 78661, that added together give a palindrome (78787).

The spelling of 12678661 in words is "twelve million, six hundred seventy-eight thousand, six hundred sixty-one".