40839 has 4 divisors (see below), whose sum is σ = 54456. Its totient is φ = 27224.

The previous prime is 40829. The next prime is 40841. The reversal of 40839 is 93804.

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 40839 - 2⁴ = 40823 is a prime.

It is a D-number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40819) 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, 6804 + ... + 6809.

It is an arithmetic number, because the mean of its divisors is an integer number (13614).

2⁴⁰⁸³⁹ is an apocalyptic number.

40839 is a deficient number, since it is larger than the sum of its proper divisors (13617).

40839 is a wasteful number, since it uses less digits than its factorization.

40839 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13616.

The product of its (nonzero) digits is 864, while the sum is 24.

The square root of 40839 is about 202.0866150936. The cubic root of 40839 is about 34.4369779939.

The spelling of 40839 in words is "forty thousand, eight hundred thirty-nine".