9991051200 has 756 divisors, whose sum is σ = 41028736840. Its totient is φ = 2285936640.

The previous prime is 9991051183. The next prime is 9991051211. The reversal of 9991051200 is 21501999.

It is a super-2 number, since 2×9991051200² (a number of 21 digits) contains 22 as substring.

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 107 ways as a sum of consecutive naturals, for example, 188510374 + ... + 188510426.

Almost surely, 2^9991051200 is an apocalyptic number.

9991051200 is a gapful number since it is divisible by the number (90) 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 9991051200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20514368420).

9991051200 is an abundant number, since it is smaller than the sum of its proper divisors (31037685640).

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

9991051200 is a wasteful number, since it uses less digits than its factorization.

9991051200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 166 (or 95 counting only the distinct ones).

The product of its (nonzero) digits is 7290, while the sum is 36.

The square root of 9991051200 is about 99955.2459853909. The cubic root of 9991051200 is about 2153.7918447321.

The spelling of 9991051200 in words is "nine billion, nine hundred ninety-one million, fifty-one thousand, two hundred".