509923 has 4 divisors (see below), whose sum is σ = 511560. Its totient is φ = 508288.

The previous prime is 509921. The next prime is 509939. The reversal of 509923 is 329905.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 329905 = 5 ⋅65981.

It is a cyclic number.

It is not a de Polignac number, because 509923 - 2¹ = 509921 is a prime.

It is a Duffinian number.

509923 is a lucky number.

It is a zygodrome in base 2.

It is a junction number, because it is equal to n+sod(n) for n = 509891 and 509900.

It is not an unprimeable number, because it can be changed into a prime (509921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 190 + ... + 1027.

It is an arithmetic number, because the mean of its divisors is an integer number (127890).

2⁵⁰⁹⁹²³ is an apocalyptic number.

509923 is a deficient number, since it is larger than the sum of its proper divisors (1637).

509923 is a wasteful number, since it uses less digits than its factorization.

509923 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1636.

The product of its (nonzero) digits is 2430, while the sum is 28.

The square root of 509923 is about 714.0889300360. The cubic root of 509923 is about 79.8916763076.

The spelling of 509923 in words is "five hundred nine thousand, nine hundred twenty-three".