45509 has 4 divisors (see below), whose sum is σ = 48204. Its totient is φ = 42816.

The previous prime is 45503. The next prime is 45523. The reversal of 45509 is 90554.

45509 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 14884 + 30625 = 122^2 + 175^2 .

It is a cyclic number.

It is not a de Polignac number, because 45509 - 2¹² = 41413 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (45503) 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, 1322 + ... + 1355.

It is an arithmetic number, because the mean of its divisors is an integer number (12051).

2⁴⁵⁵⁰⁹ is an apocalyptic number.

It is an amenable number.

45509 is a deficient number, since it is larger than the sum of its proper divisors (2695).

45509 is a wasteful number, since it uses less digits than its factorization.

45509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2694.

The product of its (nonzero) digits is 900, while the sum is 23.

The square root of 45509 is about 213.3283853593. The cubic root of 45509 is about 35.7025386128.

The spelling of 45509 in words is "forty-five thousand, five hundred nine".