81863171 has 8 divisors (see below), whose sum is σ = 88415040. Its totient is φ = 75347712.

The previous prime is 81863161. The next prime is 81863209. The reversal of 81863171 is 17136818.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81863171 - 2⁶ = 81863107 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81863161) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4331 + ... + 13508.

It is an arithmetic number, because the mean of its divisors is an integer number (11051880).

Almost surely, 2^81863171 is an apocalyptic number.

81863171 is a deficient number, since it is larger than the sum of its proper divisors (6551869).

81863171 is a wasteful number, since it uses less digits than its factorization.

81863171 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18205.

The product of its digits is 8064, while the sum is 35.

The square root of 81863171 is about 9047.8268661596. The cubic root of 81863171 is about 434.2063672732.

Adding to 81863171 its reverse (17136818), we get a palindrome (98999989).

The spelling of 81863171 in words is "eighty-one million, eight hundred sixty-three thousand, one hundred seventy-one".