12775261661 has 4 divisors (see below), whose sum is σ = 12776112000. Its totient is φ = 12774411324.

The previous prime is 12775261637. The next prime is 12775261663. The reversal of 12775261661 is 16616257721.

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.

It is a cyclic number.

It is not a de Polignac number, because 12775261661 - 2¹⁰ = 12775260637 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 (12775261663) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 402221 + ... + 432818.

It is an arithmetic number, because the mean of its divisors is an integer number (3194028000).

Almost surely, 2^12775261661 is an apocalyptic number.

It is an amenable number.

12775261661 is a deficient number, since it is larger than the sum of its proper divisors (850339).

12775261661 is an equidigital number, since it uses as much as digits as its factorization.

12775261661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 850338.

The product of its digits is 211680, while the sum is 44.

The spelling of 12775261661 in words is "twelve billion, seven hundred seventy-five million, two hundred sixty-one thousand, six hundred sixty-one".