999989081 has 16 divisors (see below), whose sum is σ = 1231622784. Its totient is φ = 790642944.

The previous prime is 999989069. The next prime is 999989083. The reversal of 999989081 is 180989999.

It is not a de Polignac number, because 999989081 - 2⁶ = 999989017 is a prime.

It is a super-2 number, since 2×999989081² = 1999956324238449122, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (999989083) 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 15 ways as a sum of consecutive naturals, for example, 167510 + ... + 173376.

It is an arithmetic number, because the mean of its divisors is an integer number (76976424).

Almost surely, 2^999989081 is an apocalyptic number.

999989081 is a gapful number since it is divisible by the number (91) formed by its first and last digit.

It is an amenable number.

999989081 is a deficient number, since it is larger than the sum of its proper divisors (231633703).

999989081 is a wasteful number, since it uses less digits than its factorization.

999989081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7760.

The product of its (nonzero) digits is 3779136, while the sum is 62.

The square root of 999989081 is about 31622.6039566637. The cubic root of 999989081 is about 999.9963603201.

The spelling of 999989081 in words is "nine hundred ninety-nine million, nine hundred eighty-nine thousand, eighty-one".