13563706663421 has 4 divisors (see below), whose sum is σ = 13574229323100. Its totient is φ = 13553184003744.

The previous prime is 13563706663379. The next prime is 13563706663457. The reversal of 13563706663421 is 12436660736531.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 12805562052196 + 758144611225 = 3578486^2 + 870715^2 .

It is a cyclic number.

It is not a de Polignac number, because 13563706663421 - 2³⁴ = 13546526794237 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 (13563706663021) 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, 5261327906 + ... + 5261330483.

It is an arithmetic number, because the mean of its divisors is an integer number (3393557330775).

Almost surely, 2^{13563706663421} is an apocalyptic number.

It is an amenable number.

13563706663421 is a deficient number, since it is larger than the sum of its proper divisors (10522659679).

13563706663421 is a wasteful number, since it uses less digits than its factorization.

13563706663421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10522659678.

The product of its (nonzero) digits is 9797760, while the sum is 53.

The spelling of 13563706663421 in words is "thirteen trillion, five hundred sixty-three billion, seven hundred six million, six hundred sixty-three thousand, four hundred twenty-one".