1091681328 has 90 divisors (see below), whose sum is σ = 2988324732. Its totient is φ = 343368000.

The previous prime is 1091681281. The next prime is 1091681413. The reversal of 1091681328 is 8231861901.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 4349203 + ... + 4349453.

Almost surely, 2^1091681328 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 1091681328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1494162366).

1091681328 is an abundant number, since it is smaller than the sum of its proper divisors (1896643404).

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

1091681328 is an equidigital number, since it uses as much as digits as its factorization.

1091681328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 551 (or 275 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 39.

The square root of 1091681328 is about 33040.6012051839. The cubic root of 1091681328 is about 1029.6713464275.

The spelling of 1091681328 in words is "one billion, ninety-one million, six hundred eighty-one thousand, three hundred twenty-eight".