9891072 has 126 divisors (see below), whose sum is σ = 30160242. Its totient is φ = 3234816.

The previous prime is 9891061. The next prime is 9891097. The reversal of 9891072 is 2701989.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 9144576 + 746496 = 3024^2 + 864^2 .

It is a super-3 number, since 3×9891072³ (a number of 22 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nialpdrome in base 6.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 13 ways as a sum of consecutive naturals, for example, 186598 + ... + 186650.

It is an arithmetic number, because the mean of its divisors is an integer number (239367).

Almost surely, 2^9891072 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 9891072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15080121).

9891072 is an abundant number, since it is smaller than the sum of its proper divisors (20269170).

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

9891072 is an frugal number, since it uses more digits than its factorization.

9891072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87 (or 58 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 36.

The square root of 9891072 is about 3145.0074721692. The cubic root of 9891072 is about 214.6583504788.

The spelling of 9891072 in words is "nine million, eight hundred ninety-one thousand, seventy-two".