991120000 has 160 divisors (see below), whose sum is σ = 2659914180. Its totient is φ = 365568000.

The previous prime is 991119989. The next prime is 991120049. The reversal of 991120000 is 21199.

It can be written as a sum of positive squares in 10 ways, for example, as 245611584 + 745508416 = 15672^2 + 27304^2 .

It is a tau number, because it is divible by the number of its divisors (160).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1039524 + ... + 1040476.

Almost surely, 2^991120000 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 991120000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1329957090).

991120000 is an abundant number, since it is smaller than the sum of its proper divisors (1668794180).

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

991120000 is an equidigital number, since it uses as much as digits as its factorization.

991120000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1000 (or 973 counting only the distinct ones).

The product of its (nonzero) digits is 162, while the sum is 22.

The square root of 991120000 is about 31482.0583825137. The cubic root of 991120000 is about 997.0311949185.

Adding to 991120000 its reverse (21199), we get a palindrome (991141199).

The spelling of 991120000 in words is "nine hundred ninety-one million, one hundred twenty thousand".