199808990 has 64 divisors (see below), whose sum is σ = 395176320. Its totient is φ = 72437760.

The previous prime is 199808969. The next prime is 199809011. The reversal of 199808990 is 99808991.

It is an interprime number because it is at equal distance from previous prime (199808969) and next prime (199809011).

It is a congruent number.

It is an unprimeable number.

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 in 31 ways as a sum of consecutive naturals, for example, 759599 + ... + 759861.

It is an arithmetic number, because the mean of its divisors is an integer number (6174630).

Almost surely, 2^199808990 is an apocalyptic number.

199808990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

199808990 is a deficient number, since it is larger than the sum of its proper divisors (195367330).

199808990 is a wasteful number, since it uses less digits than its factorization.

199808990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 437.

The product of its (nonzero) digits is 419904, while the sum is 53.

The square root of 199808990 is about 14135.3807872303. The cubic root of 199808990 is about 584.6173161338.

Subtracting from 199808990 its reverse (99808991), we obtain a palindrome (99999999).

The spelling of 199808990 in words is "one hundred ninety-nine million, eight hundred eight thousand, nine hundred ninety".