991100000 has 288 divisors, whose sum is σ = 2870253792. Its totient is φ = 332800000.

The previous prime is 991099973. The next prime is 991100081. The reversal of 991100000 is 1199.

991100000 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a nialpdrome in base 10.

It is a zygodrome in base 10.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 18699974 + ... + 18700026.

It is an arithmetic number, because the mean of its divisors is an integer number (9966159).

Almost surely, 2^991100000 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 991100000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1435126896).

991100000 is an abundant number, since it is smaller than the sum of its proper divisors (1879153792).

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

991100000 is a wasteful number, since it uses less digits than its factorization.

991100000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 116 (or 88 counting only the distinct ones).

The product of its (nonzero) digits is 81, while the sum is 20.

The square root of 991100000 is about 31481.7407396732. The cubic root of 991100000 is about 997.0244884457.

Adding to 991100000 its reverse (1199), we get a palindrome (991101199).

The spelling of 991100000 in words is "nine hundred ninety-one million, one hundred thousand".