12261661 has 4 divisors (see below), whose sum is σ = 12268800. Its totient is φ = 12254524.

The previous prime is 12261659. The next prime is 12261677. The reversal of 12261661 is 16616221.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 12261661 - 2¹ = 12261659 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 (12261611) 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, 750 + ... + 5008.

It is an arithmetic number, because the mean of its divisors is an integer number (3067200).

Almost surely, 2^12261661 is an apocalyptic number.

It is an amenable number.

12261661 is a deficient number, since it is larger than the sum of its proper divisors (7139).

12261661 is an equidigital number, since it uses as much as digits as its factorization.

12261661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7138.

The product of its digits is 864, while the sum is 25.

The square root of 12261661 is about 3501.6654608914. The cubic root of 12261661 is about 230.5949373887.

Adding to 12261661 its reverse (16616221), we get a palindrome (28877882).

The spelling of 12261661 in words is "twelve million, two hundred sixty-one thousand, six hundred sixty-one".