998591563 has 4 divisors (see below), whose sum is σ = 1019838240. Its totient is φ = 977344888.

The previous prime is 998591549. The next prime is 998591567. The reversal of 998591563 is 365195899.

998591563 is digitally balanced in base 2, 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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-998591563 is a prime.

It is a super-3 number, since 3×998591563³ (a number of 28 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (998591567) 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, 10623268 + ... + 10623361.

It is an arithmetic number, because the mean of its divisors is an integer number (254959560).

Almost surely, 2^998591563 is an apocalyptic number.

998591563 is a deficient number, since it is larger than the sum of its proper divisors (21246677).

998591563 is a wasteful number, since it uses less digits than its factorization.

998591563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21246676.

The product of its digits is 2624400, while the sum is 55.

The square root of 998591563 is about 31600.4994106106. The cubic root of 998591563 is about 999.5303004168.

The spelling of 998591563 in words is "nine hundred ninety-eight million, five hundred ninety-one thousand, five hundred sixty-three".