989979988 has 12 divisors (see below), whose sum is σ = 1769326272. Its totient is φ = 484458200.

The previous prime is 989979983. The next prime is 989980003. The reversal of 989979988 is 889979989.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (989979983) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2632738 + ... + 2633113.

It is an arithmetic number, because the mean of its divisors is an integer number (147443856).

Almost surely, 2^989979988 is an apocalyptic number.

It is an amenable number.

989979988 is a deficient number, since it is larger than the sum of its proper divisors (779346284).

989979988 is a wasteful number, since it uses less digits than its factorization.

989979988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5265902 (or 5265900 counting only the distinct ones).

The product of its digits is 211631616, while the sum is 76.

The square root of 989979988 is about 31463.9474319418. The cubic root of 989979988 is about 996.6487778557.

Subtracting from 989979988 its reverse (889979989), we obtain a palindrome (99999999).

The spelling of 989979988 in words is "nine hundred eighty-nine million, nine hundred seventy-nine thousand, nine hundred eighty-eight".