9998509 has 4 divisors (see below), whose sum is σ = 10026720. Its totient is φ = 9970300.

The previous prime is 9998479. The next prime is 9998539. The reversal of 9998509 is 9058999.

9998509 is digitally balanced in base 3, 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, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (9998479) and next prime (9998539).

It is a cyclic number.

It is not a de Polignac number, because 9998509 - 2⁷ = 9998381 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9998539) 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, 13567 + ... + 14284.

It is an arithmetic number, because the mean of its divisors is an integer number (2506680).

Almost surely, 2^9998509 is an apocalyptic number.

It is an amenable number.

9998509 is a deficient number, since it is larger than the sum of its proper divisors (28211).

9998509 is a wasteful number, since it uses less digits than its factorization.

9998509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28210.

The product of its (nonzero) digits is 262440, while the sum is 49.

The square root of 9998509 is about 3162.0419035807. The cubic root of 9998509 is about 215.4327609306.

The spelling of 9998509 in words is "nine million, nine hundred ninety-eight thousand, five hundred nine".