998563987 has 2 divisors, whose sum is σ = 998563988. Its totient is φ = 998563986.

The previous prime is 998563963. The next prime is 998564009. The reversal of 998563987 is 789365899.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-998563987 is a prime.

It is a super-3 number, since 3×998563987³ (a number of 28 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not a weakly prime, because it can be changed into another prime (998563957) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499281993 + 499281994.

It is an arithmetic number, because the mean of its divisors is an integer number (499281994).

Almost surely, 2^998563987 is an apocalyptic number.

998563987 is a deficient number, since it is larger than the sum of its proper divisors (1).

998563987 is an equidigital number, since it uses as much as digits as its factorization.

998563987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 29393280, while the sum is 64.

The square root of 998563987 is about 31600.0630853801. The cubic root of 998563987 is about 999.5210996911.

The spelling of 998563987 in words is "nine hundred ninety-eight million, five hundred sixty-three thousand, nine hundred eighty-seven".