9991776 has 96 divisors (see below), whose sum is σ = 28153440. Its totient is φ = 3096576.

The previous prime is 9991771. The next prime is 9991811. The reversal of 9991776 is 6771999.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a nialpdrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9991771) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 102960 + ... + 103056.

It is an arithmetic number, because the mean of its divisors is an integer number (293265).

Almost surely, 2^9991776 is an apocalyptic number.

9991776 is a gapful number since it is divisible by the number (96) 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 9991776, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14076720).

9991776 is an abundant number, since it is smaller than the sum of its proper divisors (18161664).

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

9991776 is a wasteful number, since it uses less digits than its factorization.

9991776 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 176 (or 168 counting only the distinct ones).

The product of its digits is 214326, while the sum is 48.

The square root of 9991776 is about 3160.9770641370. The cubic root of 9991776 is about 215.3843925691.

It can be divided in two parts, 999 and 1776, that multiplied together give a square (1774224 = 1332²).

The spelling of 9991776 in words is "nine million, nine hundred ninety-one thousand, seven hundred seventy-six".