199981801836 has 18 divisors (see below), whose sum is σ = 505509554732. Its totient is φ = 66660600600.

The previous prime is 199981801813. The next prime is 199981801837. The reversal of 199981801836 is 638108189991.

199981801836 is a `hidden beast` number, since 199 + 98 + 180 + 183 + 6 = 666.

199981801836 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (18).

It is not an unprimeable number, because it can be changed into a prime (199981801837) by changing a digit.

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 5 ways as a sum of consecutive naturals, for example, 2777524990 + ... + 2777525061.

Almost surely, 2^199981801836 is an apocalyptic number.

It is an amenable number.

199981801836 is an abundant number, since it is smaller than the sum of its proper divisors (305527752896).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

199981801836 is a wasteful number, since it uses less digits than its factorization.

199981801836 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5555050061 (or 5555050056 counting only the distinct ones).

The product of its (nonzero) digits is 6718464, while the sum is 63.

The spelling of 199981801836 in words is "one hundred ninety-nine billion, nine hundred eighty-one million, eight hundred one thousand, eight hundred thirty-six".