71845 has 4 divisors (see below), whose sum is σ = 86220. Its totient is φ = 57472.

The previous prime is 71843. The next prime is 71849. The reversal of 71845 is 54817.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 34596 + 37249 = 186^2 + 193^2 .

It is a cyclic number.

It is not a de Polignac number, because 71845 - 2¹ = 71843 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71843) 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 in 3 ways as a sum of consecutive naturals, for example, 7180 + ... + 7189.

It is an arithmetic number, because the mean of its divisors is an integer number (21555).

2⁷¹⁸⁴⁵ is an apocalyptic number.

It is an amenable number.

71845 is a deficient number, since it is larger than the sum of its proper divisors (14375).

71845 is a wasteful number, since it uses less digits than its factorization.

71845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14374.

The product of its digits is 1120, while the sum is 25.

The square root of 71845 is about 268.0391762411. The cubic root of 71845 is about 41.5718019582.

It can be divided in two parts, 71 and 845, that multiplied together give a palindrome (59995).

The spelling of 71845 in words is "seventy-one thousand, eight hundred forty-five".