80891 has 4 divisors (see below), whose sum is σ = 84432. Its totient is φ = 77352.

The previous prime is 80863. The next prime is 80897. The reversal of 80891 is 19808.

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

It is a cyclic number.

It is not a de Polignac number, because 80891 - 2¹⁰ = 79867 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 80891.

It is not an unprimeable number, because it can be changed into a prime (80897) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1736 + ... + 1781.

It is an arithmetic number, because the mean of its divisors is an integer number (21108).

2⁸⁰⁸⁹¹ is an apocalyptic number.

80891 is a deficient number, since it is larger than the sum of its proper divisors (3541).

80891 is a wasteful number, since it uses less digits than its factorization.

80891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3540.

The product of its (nonzero) digits is 576, while the sum is 26.

The square root of 80891 is about 284.4134314690. The cubic root of 80891 is about 43.2480703473.

The spelling of 80891 in words is "eighty thousand, eight hundred ninety-one".