81548538171 has 4 divisors (see below), whose sum is σ = 108731384232. Its totient is φ = 54365692112.

The previous prime is 81548538121. The next prime is 81548538223. The reversal of 81548538171 is 17183584518.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 81548538171 - 2²⁶ = 81481429307 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81548538121) 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 3 ways as a sum of consecutive naturals, for example, 13591423026 + ... + 13591423031.

It is an arithmetic number, because the mean of its divisors is an integer number (27182846058).

Almost surely, 2^81548538171 is an apocalyptic number.

81548538171 is a deficient number, since it is larger than the sum of its proper divisors (27182846061).

81548538171 is a wasteful number, since it uses less digits than its factorization.

81548538171 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27182846060.

The product of its digits is 1075200, while the sum is 51.

The spelling of 81548538171 in words is "eighty-one billion, five hundred forty-eight million, five hundred thirty-eight thousand, one hundred seventy-one".