21173543271 has 12 divisors (see below), whose sum is σ = 30587085360. Its totient is φ = 14114274720.

The previous prime is 21173543173. The next prime is 21173543311. The reversal of 21173543271 is 17234537112.

21173543271 is a `hidden beast` number, since 21 + 1 + 73 + 543 + 27 + 1 = 666.

It is not a de Polignac number, because 21173543271 - 2⁷ = 21173543143 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21173543071) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19686 + ... + 206723.

It is an arithmetic number, because the mean of its divisors is an integer number (2548923780).

Almost surely, 2^21173543271 is an apocalyptic number.

21173543271 is a deficient number, since it is larger than the sum of its proper divisors (9413542089).

21173543271 is a wasteful number, since it uses less digits than its factorization.

21173543271 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 236806 (or 236803 counting only the distinct ones).

The product of its digits is 35280, while the sum is 36.

The spelling of 21173543271 in words is "twenty-one billion, one hundred seventy-three million, five hundred forty-three thousand, two hundred seventy-one".