998603521 has 2 divisors, whose sum is σ = 998603522. Its totient is φ = 998603520.

The previous prime is 998603509. The next prime is 998603531. The reversal of 998603521 is 125306899.

It is a happy number.

998603521 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 741963121 + 256640400 = 27239^2 + 16020^2 .

It is an emirp because it is prime and its reverse (125306899) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 998603521 - 2⁹ = 998603009 is a prime.

It is not a weakly prime, because it can be changed into another prime (998603531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499301760 + 499301761.

It is an arithmetic number, because the mean of its divisors is an integer number (499301761).

Almost surely, 2^998603521 is an apocalyptic number.

It is an amenable number.

998603521 is a deficient number, since it is larger than the sum of its proper divisors (1).

998603521 is an equidigital number, since it uses as much as digits as its factorization.

998603521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 116640, while the sum is 43.

The square root of 998603521 is about 31600.6886159147. The cubic root of 998603521 is about 999.5342901480.

The spelling of 998603521 in words is "nine hundred ninety-eight million, six hundred three thousand, five hundred twenty-one".