11381321328 has 160 divisors (see below), whose sum is σ = 33639513600. Its totient is φ = 3286821888.

The previous prime is 11381321327. The next prime is 11381321351. The reversal of 11381321328 is 82312318311.

It is a happy number.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11381321321) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1287901 + ... + 1296707.

It is an arithmetic number, because the mean of its divisors is an integer number (210246960).

Almost surely, 2^11381321328 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 11381321328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16819756800).

11381321328 is an abundant number, since it is smaller than the sum of its proper divisors (22258192272).

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

11381321328 is a wasteful number, since it uses less digits than its factorization.

11381321328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8959 (or 8953 counting only the distinct ones).

The product of its digits is 6912, while the sum is 33.

Adding to 11381321328 its reverse (82312318311), we get a palindrome (93693639639).

The spelling of 11381321328 in words is "eleven billion, three hundred eighty-one million, three hundred twenty-one thousand, three hundred twenty-eight".