989040991 has 16 divisors (see below), whose sum is σ = 1073772000. Its totient is φ = 907891200.

The previous prime is 989040989. The next prime is 989041021. The reversal of 989040991 is 199040989.

It is a cyclic number.

It is not a de Polignac number, because 989040991 - 2¹ = 989040989 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (989040931) 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, 111811 + ... + 120331.

It is an arithmetic number, because the mean of its divisors is an integer number (67110750).

Almost surely, 2^989040991 is an apocalyptic number.

989040991 is a deficient number, since it is larger than the sum of its proper divisors (84731009).

989040991 is a wasteful number, since it uses less digits than its factorization.

989040991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8730.

The product of its (nonzero) digits is 209952, while the sum is 49.

The square root of 989040991 is about 31449.0220992641. The cubic root of 989040991 is about 996.3335707253. Note that the first 3 decimals are identical.

The spelling of 989040991 in words is "nine hundred eighty-nine million, forty thousand, nine hundred ninety-one".