171881 has 2 divisors, whose sum is σ = 171882. Its totient is φ = 171880.

The previous prime is 171877. The next prime is 171889. The reversal of 171881 is 188171.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 160000 + 11881 = 400^2 + 109^2 .

It is an emirp because it is prime and its reverse (188171) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 171881 - 2² = 171877 is a prime.

It is a super-2 number, since 2×171881² = 59086156322, which contains 22 as substring.

It is a Chen prime.

It is equal to p₁₅₆₅₉ and since 171881 and 15659 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 171881.

It is not a weakly prime, because it can be changed into another prime (171889) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 85940 + 85941.

It is an arithmetic number, because the mean of its divisors is an integer number (85941).

2¹⁷¹⁸⁸¹ is an apocalyptic number.

It is an amenable number.

171881 is a deficient number, since it is larger than the sum of its proper divisors (1).

171881 is an equidigital number, since it uses as much as digits as its factorization.

171881 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 448, while the sum is 26.

The square root of 171881 is about 414.5853350035. The cubic root of 171881 is about 55.6001492327.

Subtracting 171881 from its reverse (188171), we obtain a triangular number (16290 = T₁₈₀).

The spelling of 171881 in words is "one hundred seventy-one thousand, eight hundred eighty-one".