539809 has 4 divisors (see below), whose sum is σ = 568240. Its totient is φ = 511380.

The previous prime is 539797. The next prime is 539837. The reversal of 539809 is 908935.

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, and also an emirpimes, since its reverse is a distinct semiprime: 908935 = 5 ⋅181787.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-539809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (539839) 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, 14187 + ... + 14224.

It is an arithmetic number, because the mean of its divisors is an integer number (142060).

2⁵³⁹⁸⁰⁹ is an apocalyptic number.

It is an amenable number.

539809 is a deficient number, since it is larger than the sum of its proper divisors (28431).

539809 is a wasteful number, since it uses less digits than its factorization.

539809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28430.

The product of its (nonzero) digits is 9720, while the sum is 34.

The square root of 539809 is about 734.7169523020. The cubic root of 539809 is about 81.4229263700.

The spelling of 539809 in words is "five hundred thirty-nine thousand, eight hundred nine".