1991208032 has 48 divisors (see below), whose sum is σ = 4295918592. Its totient is φ = 901000320.

The previous prime is 1991208019. The next prime is 1991208053. The reversal of 1991208032 is 2308021991.

It is a junction number, because it is equal to n+sod(n) for n = 1991207983 and 1991208001.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 65813 + ... + 91179.

It is an arithmetic number, because the mean of its divisors is an integer number (89498304).

Almost surely, 2^1991208032 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 1991208032, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2147959296).

1991208032 is an abundant number, since it is smaller than the sum of its proper divisors (2304710560).

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

1991208032 is a wasteful number, since it uses less digits than its factorization.

1991208032 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25611 (or 25603 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 35.

The square root of 1991208032 is about 44622.9540931570. The cubic root of 1991208032 is about 1258.0721403913.

The spelling of 1991208032 in words is "one billion, nine hundred ninety-one million, two hundred eight thousand, thirty-two".