509545 has 8 divisors (see below), whose sum is σ = 618120. Its totient is φ = 403200.

The previous prime is 509543. The next prime is 509549. The reversal of 509545 is 545905.

509545 is a nontrivial binomial coefficient, being equal to C(1010, 2).

It can be written as a sum of positive squares in 4 ways, for example, as 123904 + 385641 = 352^2 + 621^2 .

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

It is not a de Polignac number, because 509545 - 2¹ = 509543 is a prime.

It is a super-2 number, since 2×509545² = 519272214050, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (509543) 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 7 ways as a sum of consecutive naturals, for example, 1 + ... + 1009.

It is an arithmetic number, because the mean of its divisors is an integer number (77265).

2⁵⁰⁹⁵⁴⁵ is an apocalyptic number.

509545 is the 1009-th triangular number and also the 505-th hexagonal number.

509545 is the 337-th centered nonagonal number.

It is an amenable number.

509545 is a deficient number, since it is larger than the sum of its proper divisors (108575).

509545 is a wasteful number, since it uses less digits than its factorization.

509545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1115.

The product of its (nonzero) digits is 4500, while the sum is 28.

The square root of 509545 is about 713.8242080513. The cubic root of 509545 is about 79.8719305036.

The spelling of 509545 in words is "five hundred nine thousand, five hundred forty-five".