40891 has 4 divisors (see below), whose sum is σ = 41392. Its totient is φ = 40392.

The previous prime is 40883. The next prime is 40897. The reversal of 40891 is 19804.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 40891 - 2³ = 40883 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (40897) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 96 + ... + 301.

It is an arithmetic number, because the mean of its divisors is an integer number (10348).

2⁴⁰⁸⁹¹ is an apocalyptic number.

40891 is a deficient number, since it is larger than the sum of its proper divisors (501).

40891 is a wasteful number, since it uses less digits than its factorization.

40891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 500.

The product of its (nonzero) digits is 288, while the sum is 22.

The square root of 40891 is about 202.2152318694. The cubic root of 40891 is about 34.4515879122.

It can be divided in two parts, 408 and 91, that multiplied together give a triangular number (37128 = T₂₇₂).

The spelling of 40891 in words is "forty thousand, eight hundred ninety-one".