13556206341991 has 2 divisors, whose sum is σ = 13556206341992. Its totient is φ = 13556206341990.

The previous prime is 13556206341959. The next prime is 13556206342031. The reversal of 13556206341991 is 19914360265531.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 13556206341991 - 2⁵ = 13556206341959 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13556206345991) 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 as a sum of consecutive naturals, namely, 6778103170995 + 6778103170996.

It is an arithmetic number, because the mean of its divisors is an integer number (6778103170996).

Almost surely, 2^{13556206341991} is an apocalyptic number.

13556206341991 is a deficient number, since it is larger than the sum of its proper divisors (1).

13556206341991 is an equidigital number, since it uses as much as digits as its factorization.

13556206341991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5248800, while the sum is 55.

The spelling of 13556206341991 in words is "thirteen trillion, five hundred fifty-six billion, two hundred six million, three hundred forty-one thousand, nine hundred ninety-one".