9991072 has 96 divisors (see below), whose sum is σ = 25062912. Its totient is φ = 3815424.

The previous prime is 9991067. The next prime is 9991123. The reversal of 9991072 is 2701999.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 136828 + ... + 136900.

It is an arithmetic number, because the mean of its divisors is an integer number (261072).

Almost surely, 2^9991072 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 9991072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12531456).

9991072 is an abundant number, since it is smaller than the sum of its proper divisors (15071840).

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

9991072 is a wasteful number, since it uses less digits than its factorization.

9991072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 150 (or 142 counting only the distinct ones).

The product of its (nonzero) digits is 10206, while the sum is 37.

The square root of 9991072 is about 3160.8657042019. The cubic root of 9991072 is about 215.3793339364.

The spelling of 9991072 in words is "nine million, nine hundred ninety-one thousand, seventy-two".