989917887 has 16 divisors (see below), whose sum is σ = 1529112320. Its totient is φ = 557917632.

The previous prime is 989917811. The next prime is 989917889. The reversal of 989917887 is 788719989.

It is not a de Polignac number, because 989917887 - 2¹⁸ = 989655743 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 (989917889) 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 15 ways as a sum of consecutive naturals, for example, 321337 + ... + 324402.

It is an arithmetic number, because the mean of its divisors is an integer number (95569520).

Almost surely, 2^989917887 is an apocalyptic number.

989917887 is a deficient number, since it is larger than the sum of its proper divisors (539194433).

989917887 is a wasteful number, since it uses less digits than its factorization.

989917887 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 645822.

The product of its digits is 18289152, while the sum is 66.

The square root of 989917887 is about 31462.9605568198. The cubic root of 989917887 is about 996.6279376431.

The spelling of 989917887 in words is "nine hundred eighty-nine million, nine hundred seventeen thousand, eight hundred eighty-seven".