12721061601 has 12 divisors (see below), whose sum is σ = 18375889428. Its totient is φ = 8480235744.

The previous prime is 12721061579. The next prime is 12721061627. The reversal of 12721061601 is 10616012721.

It is a happy number.

12721061601 is a `hidden beast` number, since 1 + 27 + 21 + 0 + 616 + 0 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 2685830625 + 10035230976 = 51825^2 + 100176^2 .

It is not a de Polignac number, because 12721061601 - 2⁵ = 12721061569 is a prime.

It is not an unprimeable number, because it can be changed into a prime (12721061641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 224511 + ... + 275403.

It is an arithmetic number, because the mean of its divisors is an integer number (1531324119).

Almost surely, 2^12721061601 is an apocalyptic number.

It is an amenable number.

12721061601 is a deficient number, since it is larger than the sum of its proper divisors (5654827827).

12721061601 is a wasteful number, since it uses less digits than its factorization.

12721061601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78672 (or 78669 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 27.

The spelling of 12721061601 in words is "twelve billion, seven hundred twenty-one million, sixty-one thousand, six hundred one".