90509 has 4 divisors (see below), whose sum is σ = 93660. Its totient is φ = 87360.

The previous prime is 90499. The next prime is 90511.

90509 is nontrivially palindromic in base 10.

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 + 75625 = 122^2 + 275^2 .

It is a cyclic number.

It is not a de Polignac number, because 90509 - 2¹² = 86413 is a prime.

It is an alternating number because its digits alternate between odd and even.

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 (90529) 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, 1532 + ... + 1589.

It is an arithmetic number, because the mean of its divisors is an integer number (23415).

2⁹⁰⁵⁰⁹ is an apocalyptic number.

It is an amenable number.

90509 is a deficient number, since it is larger than the sum of its proper divisors (3151).

90509 is a wasteful number, since it uses less digits than its factorization.

90509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3150.

The product of its (nonzero) digits is 405, while the sum is 23.

The square root of 90509 is about 300.8471372641. The cubic root of 90509 is about 44.8983714768.

The spelling of 90509 in words is "ninety thousand, five hundred nine".