9991156 has 24 divisors (see below), whose sum is σ = 20079360. Its totient is φ = 4261152.

The previous prime is 9991151. The next prime is 9991159. The reversal of 9991156 is 6511999.

It is a hoax number, since the sum of its digits (40) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9991151) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5946 + ... + 7438.

It is an arithmetic number, because the mean of its divisors is an integer number (836640).

Almost surely, 2^9991156 is an apocalyptic number.

It is an amenable number.

9991156 is an abundant number, since it is smaller than the sum of its proper divisors (10088204).

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

9991156 is a wasteful number, since it uses less digits than its factorization.

9991156 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1743 (or 1741 counting only the distinct ones).

The product of its digits is 21870, while the sum is 40.

The square root of 9991156 is about 3160.8789916730. The cubic root of 9991156 is about 215.3799375358.

The spelling of 9991156 in words is "nine million, nine hundred ninety-one thousand, one hundred fifty-six".