991745118 has 96 divisors (see below), whose sum is σ = 2730104832. Its totient is φ = 253108800.

The previous prime is 991745113. The next prime is 991745143. The reversal of 991745118 is 811547199.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991745113) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 41013 + ... + 60543.

It is an arithmetic number, because the mean of its divisors is an integer number (28438592).

Almost surely, 2^991745118 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 991745118, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1365052416).

991745118 is an abundant number, since it is smaller than the sum of its proper divisors (1738359714).

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

991745118 is a wasteful number, since it uses less digits than its factorization.

991745118 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19590 (or 19587 counting only the distinct ones).

The product of its digits is 90720, while the sum is 45.

The square root of 991745118 is about 31491.9849803089. The cubic root of 991745118 is about 997.2407662984.

The spelling of 991745118 in words is "nine hundred ninety-one million, seven hundred forty-five thousand, one hundred eighteen".