9991274400 has 288 divisors, whose sum is σ = 36577033920. Its totient is φ = 2631767040.

The previous prime is 9991274353. The next prime is 9991274407. The reversal of 9991274400 is 44721999.

It is a happy number.

9991274400 is a `hidden beast` number, since 99 + 91 + 2 + 74 + 400 = 666.

9991274400 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (288).

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

It is not an unprimeable number, because it can be changed into a prime (9991274407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1790014 + ... + 1795586.

It is an arithmetic number, because the mean of its divisors is an integer number (127003590).

Almost surely, 2^9991274400 is an apocalyptic number.

9991274400 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 9991274400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18288516960).

9991274400 is an abundant number, since it is smaller than the sum of its proper divisors (26585759520).

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

9991274400 is a wasteful number, since it uses less digits than its factorization.

9991274400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5685 (or 5666 counting only the distinct ones).

The product of its (nonzero) digits is 163296, while the sum is 45.

The square root of 9991274400 is about 99956.3624788337. The cubic root of 9991274400 is about 2153.8078831766.

The spelling of 9991274400 in words is "nine billion, nine hundred ninety-one million, two hundred seventy-four thousand, four hundred".