40389 has 4 divisors (see below), whose sum is σ = 53856. Its totient is φ = 26924.

The previous prime is 40387. The next prime is 40423. The reversal of 40389 is 98304.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 40389 - 2¹ = 40387 is a prime.

It is a D-number.

It is a Curzon number.

40389 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40387) 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, 6729 + ... + 6734.

It is an arithmetic number, because the mean of its divisors is an integer number (13464).

2⁴⁰³⁸⁹ is an apocalyptic number.

It is an amenable number.

40389 is a deficient number, since it is larger than the sum of its proper divisors (13467).

40389 is a wasteful number, since it uses less digits than its factorization.

40389 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13466.

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

The square root of 40389 is about 200.9701470368. The cubic root of 40389 is about 34.3100249209.

The spelling of 40389 in words is "forty thousand, three hundred eighty-nine".