71881 has 2 divisors, whose sum is σ = 71882. Its totient is φ = 71880.

The previous prime is 71879. The next prime is 71887. The reversal of 71881 is 18817.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 38025 + 33856 = 195^2 + 184^2 .

It is a cyclic number.

It is not a de Polignac number, because 71881 - 2¹ = 71879 is a prime.

It is a super-2 number, since 2×71881² = 10333756322, which contains 22 as substring.

Together with 71879, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (71887) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35940 + 35941.

It is an arithmetic number, because the mean of its divisors is an integer number (35941).

2⁷¹⁸⁸¹ is an apocalyptic number.

It is an amenable number.

71881 is a deficient number, since it is larger than the sum of its proper divisors (1).

71881 is an equidigital number, since it uses as much as digits as its factorization.

71881 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 448, while the sum is 25.

The square root of 71881 is about 268.1063221933. The cubic root of 71881 is about 41.5787443804.

The spelling of 71881 in words is "seventy-one thousand, eight hundred eighty-one".