990199993 has 2 divisors, whose sum is σ = 990199994. Its totient is φ = 990199992.

The previous prime is 990199981. The next prime is 990200011. The reversal of 990199993 is 399991099.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 665227264 + 324972729 = 25792^2 + 18027^2 .

It is an emirp because it is prime and its reverse (399991099) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 990199993 - 2⁹ = 990199481 is a prime.

It is a super-2 number, since 2×990199993² = 1960992052274400098, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (990199393) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495099996 + 495099997.

It is an arithmetic number, because the mean of its divisors is an integer number (495099997).

Almost surely, 2^990199993 is an apocalyptic number.

It is an amenable number.

990199993 is a deficient number, since it is larger than the sum of its proper divisors (1).

990199993 is an equidigital number, since it uses as much as digits as its factorization.

990199993 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1594323, while the sum is 58.

The square root of 990199993 is about 31467.4433820099. The cubic root of 990199993 is about 996.7226013929.

The spelling of 990199993 in words is "nine hundred ninety million, one hundred ninety-nine thousand, nine hundred ninety-three".