53509 has 4 divisors (see below), whose sum is σ = 54316. Its totient is φ = 52704.

The previous prime is 53507. The next prime is 53527. The reversal of 53509 is 90535.

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 44100 + 9409 = 210^2 + 97^2 .

It is a cyclic number.

It is not a de Polignac number, because 53509 - 2¹ = 53507 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 53509.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (53503) 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, 294 + ... + 439.

It is an arithmetic number, because the mean of its divisors is an integer number (13579).

2⁵³⁵⁰⁹ is an apocalyptic number.

It is an amenable number.

53509 is a deficient number, since it is larger than the sum of its proper divisors (807).

53509 is an equidigital number, since it uses as much as digits as its factorization.

53509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 806.

The product of its (nonzero) digits is 675, while the sum is 22.

The square root of 53509 is about 231.3201245028. The cubic root of 53509 is about 37.6827230299.

The spelling of 53509 in words is "fifty-three thousand, five hundred nine".