509605 has 4 divisors (see below), whose sum is σ = 611532. Its totient is φ = 407680.

The previous prime is 509603. The next prime is 509623. The reversal of 509605 is 506905.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 66049 + 443556 = 257^2 + 666^2 .

It is not a de Polignac number, because 509605 - 2¹ = 509603 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 509605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (509603) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 50956 + ... + 50965.

It is an arithmetic number, because the mean of its divisors is an integer number (152883).

2⁵⁰⁹⁶⁰⁵ is an apocalyptic number.

It is an amenable number.

509605 is a deficient number, since it is larger than the sum of its proper divisors (101927).

509605 is a wasteful number, since it uses less digits than its factorization.

509605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 101926.

The product of its (nonzero) digits is 1350, while the sum is 25.

The square root of 509605 is about 713.8662339682. The cubic root of 509605 is about 79.8750654101.

The spelling of 509605 in words is "five hundred nine thousand, six hundred five".