991833930 has 128 divisors (see below), whose sum is σ = 2754259200. Its totient is φ = 253677312.

The previous prime is 991833929. The next prime is 991833937. The reversal of 991833930 is 39338199.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (991833937) 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 63 ways as a sum of consecutive naturals, for example, 1542189 + ... + 1542831.

It is an arithmetic number, because the mean of its divisors is an integer number (21517650).

Almost surely, 2^991833930 is an apocalyptic number.

991833930 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 991833930, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1377129600).

991833930 is an abundant number, since it is smaller than the sum of its proper divisors (1762425270).

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

991833930 is a wasteful number, since it uses less digits than its factorization.

991833930 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 885 (or 879 counting only the distinct ones).

The product of its (nonzero) digits is 157464, while the sum is 45.

The square root of 991833930 is about 31493.3950218137. The cubic root of 991833930 is about 997.2705334572.

The spelling of 991833930 in words is "nine hundred ninety-one million, eight hundred thirty-three thousand, nine hundred thirty".