40209 has 8 divisors (see below), whose sum is σ = 57792. Its totient is φ = 24720.

The previous prime is 40193. The next prime is 40213. The reversal of 40209 is 90204.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 40209 - 2⁴ = 40193 is a prime.

It is not an unprimeable number, because it can be changed into a prime (40289) 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 7 ways as a sum of consecutive naturals, for example, 477 + ... + 554.

It is an arithmetic number, because the mean of its divisors is an integer number (7224).

2⁴⁰²⁰⁹ is an apocalyptic number.

It is an amenable number.

40209 is a deficient number, since it is larger than the sum of its proper divisors (17583).

40209 is a wasteful number, since it uses less digits than its factorization.

40209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1047.

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 40209 is about 200.5218192616. The cubic root of 40209 is about 34.2589796549.

The spelling of 40209 in words is "forty thousand, two hundred nine".