545509 has 4 divisors (see below), whose sum is σ = 574240. Its totient is φ = 516780.

The previous prime is 545497. The next prime is 545521. The reversal of 545509 is 905545.

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 an interprime number because it is at equal distance from previous prime (545497) and next prime (545521).

It is a cyclic number.

It is not a de Polignac number, because 545509 - 2⁵ = 545477 is a prime.

It is a Duffinian number.

545509 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (545549) 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, 14337 + ... + 14374.

It is an arithmetic number, because the mean of its divisors is an integer number (143560).

2⁵⁴⁵⁵⁰⁹ is an apocalyptic number.

It is an amenable number.

545509 is a deficient number, since it is larger than the sum of its proper divisors (28731).

545509 is a wasteful number, since it uses less digits than its factorization.

545509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28730.

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

The square root of 545509 is about 738.5858108575. The cubic root of 545509 is about 81.7085129611.

The spelling of 545509 in words is "five hundred forty-five thousand, five hundred nine".