118509 has 4 divisors (see below), whose sum is σ = 158016. Its totient is φ = 79004.

The previous prime is 118493. The next prime is 118529. The reversal of 118509 is 905811.

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 118509 - 2⁴ = 118493 is a prime.

It is a D-number.

It is a Curzon number.

118509 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (118529) 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, 19749 + ... + 19754.

It is an arithmetic number, because the mean of its divisors is an integer number (39504).

2¹¹⁸⁵⁰⁹ is an apocalyptic number.

It is an amenable number.

118509 is a deficient number, since it is larger than the sum of its proper divisors (39507).

118509 is an equidigital number, since it uses as much as digits as its factorization.

118509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39506.

The product of its (nonzero) digits is 360, while the sum is 24.

The square root of 118509 is about 344.2513616531. The cubic root of 118509 is about 49.1191049521.

The spelling of 118509 in words is "one hundred eighteen thousand, five hundred nine".