993998209 has 2 divisors, whose sum is σ = 993998210. Its totient is φ = 993998208.

The previous prime is 993998207. The next prime is 993998237. The reversal of 993998209 is 902899399.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 755975025 + 238023184 = 27495^2 + 15428^2 .

It is a cyclic number.

It is not a de Polignac number, because 993998209 - 2¹ = 993998207 is a prime.

Together with 993998207, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (993998207) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 496999104 + 496999105.

It is an arithmetic number, because the mean of its divisors is an integer number (496999105).

Almost surely, 2^993998209 is an apocalyptic number.

It is an amenable number.

993998209 is a deficient number, since it is larger than the sum of its proper divisors (1).

993998209 is an equidigital number, since it uses as much as digits as its factorization.

993998209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2834352, while the sum is 58.

The square root of 993998209 is about 31527.7371373208. The cubic root of 993998209 is about 997.9953872127.

The spelling of 993998209 in words is "nine hundred ninety-three million, nine hundred ninety-eight thousand, two hundred nine".