9991000098000 has 120 divisors (see below), whose sum is σ = 34895233071816. Its totient is φ = 2664266688000.

The previous prime is 9991000097977. The next prime is 9991000098041. The reversal of 9991000098000 is 8900001999.

It can be written as a sum of positive squares in 4 ways, for example, as 6562944144 + 9984437153856 = 81012^2 + 3159816^2 .

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 277509781 + ... + 277545780.

Almost surely, 2^{9991000098000} is an apocalyptic number.

9991000098000 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

9991000098000 is an abundant number, since it is smaller than the sum of its proper divisors (24904232973816).

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

9991000098000 is a wasteful number, since it uses less digits than its factorization.

9991000098000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 555055590 (or 555055571 counting only the distinct ones).

The product of its (nonzero) digits is 52488, while the sum is 45.

Adding to 9991000098000 its reverse (8900001999), we get a palindrome (9999900099999).

The spelling of 9991000098000 in words is "nine trillion, nine hundred ninety-one billion, ninety-eight thousand".