999998563 has 2 divisors, whose sum is σ = 999998564. Its totient is φ = 999998562.

The previous prime is 999998537. The next prime is 999998609. The reversal of 999998563 is 365899999.

It is a weak prime.

It is an emirp because it is prime and its reverse (365899999) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-999998563 is a prime.

It is not a weakly prime, because it can be changed into another prime (999998533) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499999281 + 499999282.

It is an arithmetic number, because the mean of its divisors is an integer number (499999282).

Almost surely, 2^999998563 is an apocalyptic number.

999998563 is a deficient number, since it is larger than the sum of its proper divisors (1).

999998563 is an equidigital number, since it uses as much as digits as its factorization.

999998563 is an evil number, because the sum of its binary digits is even.

The product of its digits is 42515280, while the sum is 67.

The square root of 999998563 is about 31622.7538807106. The cubic root of 999998563 is about 999.9995209998. Note that the first 3 decimals are identical.

The spelling of 999998563 in words is "nine hundred ninety-nine million, nine hundred ninety-eight thousand, five hundred sixty-three".