71811 has 12 divisors (see below), whose sum is σ = 106080. Its totient is φ = 46800.

The previous prime is 71809. The next prime is 71821. The reversal of 71811 is 11817.

It is not a de Polignac number, because 71811 - 2¹ = 71809 is a prime.

It is a plaindrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (71821) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 661 + ... + 761.

It is an arithmetic number, because the mean of its divisors is an integer number (8840).

2⁷¹⁸¹¹ is an apocalyptic number.

71811 is a deficient number, since it is larger than the sum of its proper divisors (34269).

71811 is a wasteful number, since it uses less digits than its factorization.

71811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 186 (or 183 counting only the distinct ones).

The product of its digits is 56, while the sum is 18.

The square root of 71811 is about 267.9757451711. The cubic root of 71811 is about 41.5652430963.

It can be divided in two parts, 718 and 11, that added together give a 6-th power (729 = 3⁶).

The spelling of 71811 in words is "seventy-one thousand, eight hundred eleven".