89991000000 has 980 divisors, whose sum is σ = 367362641448. Its totient is φ = 21600000000.

The previous prime is 89990999957. The next prime is 89991000013. The reversal of 89991000000 is 19998.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 139 ways as a sum of consecutive naturals, for example, 890999950 + ... + 891000050.

Almost surely, 2^89991000000 is an apocalyptic number.

89991000000 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 89991000000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (183681320724).

89991000000 is an abundant number, since it is smaller than the sum of its proper divisors (277371641448).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

89991000000 is an equidigital number, since it uses as much as digits as its factorization.

89991000000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166 (or 122 counting only the distinct ones).

The product of its (nonzero) digits is 5832, while the sum is 36.

Adding to 89991000000 its reverse (19998), we get a palindrome (89991019998).

The spelling of 89991000000 in words is "eighty-nine billion, nine hundred ninety-one million", and thus it is an aban number.