12536605721 has 8 divisors (see below), whose sum is σ = 12980822400. Its totient is φ = 12093183760.

The previous prime is 12536605703. The next prime is 12536605733. The reversal of 12536605721 is 12750663521.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 12536605721 - 2¹⁰ = 12536604697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12536605121) 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 7 ways as a sum of consecutive naturals, for example, 166481 + ... + 229758.

It is an arithmetic number, because the mean of its divisors is an integer number (1622602800).

Almost surely, 2^12536605721 is an apocalyptic number.

It is an amenable number.

12536605721 is a deficient number, since it is larger than the sum of its proper divisors (444216679).

12536605721 is a wasteful number, since it uses less digits than its factorization.

12536605721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 397359.

The product of its (nonzero) digits is 75600, while the sum is 38.

The spelling of 12536605721 in words is "twelve billion, five hundred thirty-six million, six hundred five thousand, seven hundred twenty-one".