998570809 has 4 divisors (see below), whose sum is σ = 998764416. Its totient is φ = 998377204.

The previous prime is 998570777. The next prime is 998570831. The reversal of 998570809 is 908075899.

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 998570809 - 2⁵ = 998570777 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 998570809.

It is not an unprimeable number, because it can be changed into a prime (998570849) 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, 88849 + ... + 99454.

It is an arithmetic number, because the mean of its divisors is an integer number (249691104).

Almost surely, 2^998570809 is an apocalyptic number.

It is an amenable number.

998570809 is a deficient number, since it is larger than the sum of its proper divisors (193607).

998570809 is a wasteful number, since it uses less digits than its factorization.

998570809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 193606.

The product of its (nonzero) digits is 1632960, while the sum is 55.

The square root of 998570809 is about 31600.1710280182. The cubic root of 998570809 is about 999.5233758655.

The spelling of 998570809 in words is "nine hundred ninety-eight million, five hundred seventy thousand, eight hundred nine".