199889000981 has 2 divisors, whose sum is σ = 199889000982. Its totient is φ = 199889000980.

The previous prime is 199889000977. The next prime is 199889000999. The reversal of 199889000981 is 189000988991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 123911040100 + 75977960881 = 352010^2 + 275641^2 .

It is a cyclic number.

It is not a de Polignac number, because 199889000981 - 2² = 199889000977 is a prime.

It is a super-2 number, since 2×199889000981² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (199889000881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99944500490 + 99944500491.

It is an arithmetic number, because the mean of its divisors is an integer number (99944500491).

Almost surely, 2^199889000981 is an apocalyptic number.

It is an amenable number.

199889000981 is a deficient number, since it is larger than the sum of its proper divisors (1).

199889000981 is an equidigital number, since it uses as much as digits as its factorization.

199889000981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3359232, while the sum is 62.

The spelling of 199889000981 in words is "one hundred ninety-nine billion, eight hundred eighty-nine million, nine hundred eighty-one", and thus it is an aban number.