989199991989 has 24 divisors (see below), whose sum is σ = 1564286540544. Its totient is φ = 597381624000.

The previous prime is 989199991943. The next prime is 989199991999.

989199991989 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 989199991989 - 2⁸ = 989199991733 is a prime.

It is a super-2 number, since 2×989199991989² (a number of 25 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 989199991899 and 989199991908.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (989199991999) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 17751397 + ... + 17807034.

It is an arithmetic number, because the mean of its divisors is an integer number (65178605856).

Almost surely, 2^989199991989 is an apocalyptic number.

989199991989 is a gapful number since it is divisible by the number (99) formed by its first and last digit.

It is an amenable number.

989199991989 is a deficient number, since it is larger than the sum of its proper divisors (575086548555).

989199991989 is a wasteful number, since it uses less digits than its factorization.

989199991989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35558729 (or 35558726 counting only the distinct ones).

The product of its digits is 2754990144, while the sum is 90.

The spelling of 989199991989 in words is "nine hundred eighty-nine billion, one hundred ninety-nine million, nine hundred ninety-one thousand, nine hundred eighty-nine".