12461336561 has 4 divisors (see below), whose sum is σ = 13117196400. Its totient is φ = 11805476724.

The previous prime is 12461336551. The next prime is 12461336567. The reversal of 12461336561 is 16563316421.

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 an emirpimes, since its reverse is a distinct semiprime: 16563316421 = 2137 ⋅7750733.

It is a cyclic number.

It is not a de Polignac number, because 12461336561 - 2¹⁴ = 12461320177 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12461336567) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 327929891 + ... + 327929928.

It is an arithmetic number, because the mean of its divisors is an integer number (3279299100).

Almost surely, 2^12461336561 is an apocalyptic number.

It is an amenable number.

12461336561 is a deficient number, since it is larger than the sum of its proper divisors (655859839).

12461336561 is an equidigital number, since it uses as much as digits as its factorization.

12461336561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 655859838.

The product of its digits is 77760, while the sum is 38.

The spelling of 12461336561 in words is "twelve billion, four hundred sixty-one million, three hundred thirty-six thousand, five hundred sixty-one".