998609 has 4 divisors (see below), whose sum is σ = 1019904. Its totient is φ = 977316.

The previous prime is 998561. The next prime is 998617. The reversal of 998609 is 906899.

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 a cyclic number.

It is not a de Polignac number, because 998609 - 2⁸ = 998353 is a prime.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 998609.

It is not an unprimeable number, because it can be changed into a prime (998629) 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, 10577 + ... + 10670.

It is an arithmetic number, because the mean of its divisors is an integer number (254976).

2⁹⁹⁸⁶⁰⁹ is an apocalyptic number.

It is an amenable number.

998609 is a deficient number, since it is larger than the sum of its proper divisors (21295).

998609 is a wasteful number, since it uses less digits than its factorization.

998609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21294.

The product of its (nonzero) digits is 34992, while the sum is 41.

The square root of 998609 is about 999.3042579715. The cubic root of 998609 is about 99.9536118180.

The spelling of 998609 in words is "nine hundred ninety-eight thousand, six hundred nine".