12817661 has 2 divisors, whose sum is σ = 12817662. Its totient is φ = 12817660.

The previous prime is 12817657. The next prime is 12817667. The reversal of 12817661 is 16671821.

It is a happy number.

12817661 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12292036 + 525625 = 3506^2 + 725^2 .

It is an emirp because it is prime and its reverse (16671821) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 12817661 - 2² = 12817657 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12817667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6408830 + 6408831.

It is an arithmetic number, because the mean of its divisors is an integer number (6408831).

Almost surely, 2^12817661 is an apocalyptic number.

It is an amenable number.

12817661 is a deficient number, since it is larger than the sum of its proper divisors (1).

12817661 is an equidigital number, since it uses as much as digits as its factorization.

12817661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4032, while the sum is 32.

The square root of 12817661 is about 3580.1761129866. The cubic root of 12817661 is about 234.0289551916.

The spelling of 12817661 in words is "twelve million, eight hundred seventeen thousand, six hundred sixty-one".