71805 has 8 divisors (see below), whose sum is σ = 114912. Its totient is φ = 38288.

The previous prime is 71789. The next prime is 71807. The reversal of 71805 is 50817.

It is a happy number.

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 71805 - 2⁴ = 71789 is a prime.

It is a plaindrome in base 12.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71807) 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, 2379 + ... + 2408.

It is an arithmetic number, because the mean of its divisors is an integer number (14364).

2⁷¹⁸⁰⁵ is an apocalyptic number.

It is an amenable number.

71805 is a deficient number, since it is larger than the sum of its proper divisors (43107).

71805 is a wasteful number, since it uses less digits than its factorization.

71805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4795.

The product of its (nonzero) digits is 280, while the sum is 21.

The square root of 71805 is about 267.9645498942. The cubic root of 71805 is about 41.5640854352.

The spelling of 71805 in words is "seventy-one thousand, eight hundred five".