999000981 has 24 divisors (see below), whose sum is σ = 1657038240. Its totient is φ = 573588000.

The previous prime is 999000967. The next prime is 999000991. The reversal of 999000981 is 189000999.

It is not a de Polignac number, because 999000981 - 2⁵ = 999000949 is a prime.

It is a super-2 number, since 2×999000981² = 1996005920077924722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (999000901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 263670 + ... + 267431.

It is an arithmetic number, because the mean of its divisors is an integer number (69043260).

Almost surely, 2^999000981 is an apocalyptic number.

It is an amenable number.

999000981 is a deficient number, since it is larger than the sum of its proper divisors (658037259).

999000981 is a wasteful number, since it uses less digits than its factorization.

999000981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 531137 (or 531134 counting only the distinct ones).

The product of its (nonzero) digits is 52488, while the sum is 45.

The square root of 999000981 is about 31606.9767772876. The cubic root of 999000981 is about 999.6668827119. Note that the first 3 decimals are identical.

The spelling of 999000981 in words is "nine hundred ninety-nine million, nine hundred eighty-one", and thus it is an aban number.