99121989120 has 640 divisors, whose sum is σ = 407891607552. Its totient is φ = 19928678400.

The previous prime is 99121989103. The next prime is 99121989121. The reversal of 99121989120 is 2198912199.

It is a tau number, because it is divible by the number of its divisors (640).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99121989121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 18329457 + ... + 18334863.

Almost surely, 2^99121989120 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 99121989120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (203945803776).

99121989120 is an abundant number, since it is smaller than the sum of its proper divisors (308769618432).

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

99121989120 is a wasteful number, since it uses less digits than its factorization.

99121989120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5482 (or 5466 counting only the distinct ones).

The product of its (nonzero) digits is 209952, while the sum is 51.

The spelling of 99121989120 in words is "ninety-nine billion, one hundred twenty-one million, nine hundred eighty-nine thousand, one hundred twenty".