9999509 has 8 divisors (see below), whose sum is σ = 11060280. Its totient is φ = 8980416.

The previous prime is 9999481. The next prime is 9999511. The reversal of 9999509 is 9059999.

It can be written as a sum of positive squares in 4 ways, for example, as 3598609 + 6400900 = 1897^2 + 2530^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 9999509 - 2¹² = 9995413 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 (9996509) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9914 + ... + 10875.

It is an arithmetic number, because the mean of its divisors is an integer number (1382535).

Almost surely, 2^9999509 is an apocalyptic number.

It is an amenable number.

9999509 is a deficient number, since it is larger than the sum of its proper divisors (1060771).

9999509 is a wasteful number, since it uses less digits than its factorization.

9999509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20839.

The product of its (nonzero) digits is 295245, while the sum is 50.

The square root of 9999509 is about 3162.2000252988. The cubic root of 9999509 is about 215.4399428540.

The spelling of 9999509 in words is "nine million, nine hundred ninety-nine thousand, five hundred nine".