12345661 has 4 divisors (see below), whose sum is σ = 12578652. Its totient is φ = 12112672.

The previous prime is 12345653. The next prime is 12345701. The reversal of 12345661 is 16654321.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6125625 + 6220036 = 2475^2 + 2494^2 .

It is a cyclic number.

It is not a de Polignac number, because 12345661 - 2³ = 12345653 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12340661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 116416 + ... + 116521.

It is an arithmetic number, because the mean of its divisors is an integer number (3144663).

Almost surely, 2^12345661 is an apocalyptic number.

It is an amenable number.

12345661 is a deficient number, since it is larger than the sum of its proper divisors (232991).

12345661 is an equidigital number, since it uses as much as digits as its factorization.

12345661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 232990.

The product of its digits is 4320, while the sum is 28.

The square root of 12345661 is about 3513.6392814289. The cubic root of 12345661 is about 231.1203123819.

Adding to 12345661 its reverse (16654321), we get a palindrome (28999982).

The spelling of 12345661 in words is "twelve million, three hundred forty-five thousand, six hundred sixty-one".