99509 has 4 divisors (see below), whose sum is σ = 100320. Its totient is φ = 98700.

The previous prime is 99497. The next prime is 99523. The reversal of 99509 is 90599.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 99509 - 2¹² = 95413 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 99509.

It is not an unprimeable number, because it can be changed into a prime (99529) 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, 179 + ... + 480.

It is an arithmetic number, because the mean of its divisors is an integer number (25080).

2⁹⁹⁵⁰⁹ is an apocalyptic number.

It is an amenable number.

99509 is a deficient number, since it is larger than the sum of its proper divisors (811).

99509 is a wasteful number, since it uses less digits than its factorization.

99509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 810.

The product of its (nonzero) digits is 3645, while the sum is 32.

The square root of 99509 is about 315.4504715482. The cubic root of 99509 is about 46.3397963254.

The spelling of 99509 in words is "ninety-nine thousand, five hundred nine".