998603509 has 2 divisors, whose sum is σ = 998603510. Its totient is φ = 998603508.

The previous prime is 998603453. The next prime is 998603521. The reversal of 998603509 is 905306899.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 914881009 + 83722500 = 30247^2 + 9150^2 .

It is a cyclic number.

It is not a de Polignac number, because 998603509 - 2⁷ = 998603381 is a prime.

It is a super-2 number, since 2×998603509² = 1994417936374226162, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (998603009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499301754 + 499301755.

It is an arithmetic number, because the mean of its divisors is an integer number (499301755).

Almost surely, 2^998603509 is an apocalyptic number.

It is an amenable number.

998603509 is a deficient number, since it is larger than the sum of its proper divisors (1).

998603509 is an equidigital number, since it uses as much as digits as its factorization.

998603509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 524880, while the sum is 49.

The square root of 998603509 is about 31600.6884260454. The cubic root of 998603509 is about 999.5342861443.

The spelling of 998603509 in words is "nine hundred ninety-eight million, six hundred three thousand, five hundred nine".