989898989899081 has 2 divisors, whose sum is σ = 989898989899082. Its totient is φ = 989898989899080.

The previous prime is 989898989899049. The next prime is 989898989899103. The reversal of 989898989899081 is 180998989898989.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 984745822035600 + 5153167863481 = 31380660^2 + 2270059^2 .

It is a cyclic number.

It is not a de Polignac number, because 989898989899081 - 2⁵ = 989898989899049 is a prime.

It is a super-2 number, since 2×989898989899081² (a number of 31 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (989898989899031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 494949494949540 + 494949494949541.

It is an arithmetic number, because the mean of its divisors is an integer number (494949494949541).

Almost surely, 2^{989898989899081} is an apocalyptic number.

It is an amenable number.

989898989899081 is a deficient number, since it is larger than the sum of its proper divisors (1).

989898989899081 is an equidigital number, since it uses as much as digits as its factorization.

989898989899081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1253826625536, while the sum is 112.

The spelling of 989898989899081 in words is "nine hundred eighty-nine trillion, eight hundred ninety-eight billion, nine hundred eighty-nine million, eight hundred ninety-nine thousand, eighty-one".