81748171 has 4 divisors (see below), whose sum is σ = 81830200. Its totient is φ = 81666144.

The previous prime is 81748169. The next prime is 81748211. The reversal of 81748171 is 17184718.

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 81748171 - 2¹ = 81748169 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81748171.

It is not an unprimeable number, because it can be changed into a prime (81743171) 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, 39501 + ... + 41518.

It is an arithmetic number, because the mean of its divisors is an integer number (20457550).

Almost surely, 2^81748171 is an apocalyptic number.

81748171 is a deficient number, since it is larger than the sum of its proper divisors (82029).

81748171 is a wasteful number, since it uses less digits than its factorization.

81748171 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82028.

The product of its digits is 12544, while the sum is 37.

The square root of 81748171 is about 9041.4695155157. The cubic root of 81748171 is about 434.0029500674.

The spelling of 81748171 in words is "eighty-one million, seven hundred forty-eight thousand, one hundred seventy-one".