998606221 has 2 divisors, whose sum is σ = 998606222. Its totient is φ = 998606220.

The previous prime is 998606183. The next prime is 998606239. The reversal of 998606221 is 122606899.

998606221 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., 541074121 + 457532100 = 23261^2 + 21390^2 .

It is an emirp because it is prime and its reverse (122606899) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-998606221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (998607221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499303110 + 499303111.

It is an arithmetic number, because the mean of its divisors is an integer number (499303111).

Almost surely, 2^998606221 is an apocalyptic number.

It is an amenable number.

998606221 is a deficient number, since it is larger than the sum of its proper divisors (1).

998606221 is an equidigital number, since it uses as much as digits as its factorization.

998606221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 93312, while the sum is 43.

The square root of 998606221 is about 31600.7313364738. The cubic root of 998606221 is about 999.5351909861.

The spelling of 998606221 in words is "nine hundred ninety-eight million, six hundred six thousand, two hundred twenty-one".