11221120128 has 64 divisors (see below), whose sum is σ = 29919700800. Its totient is φ = 3726117888.

The previous prime is 11221120121. The next prime is 11221120151. The reversal of 11221120128 is 82102112211.

It is a tau number, because it is divible by the number of its divisors (64).

It is not an unprimeable number, because it can be changed into a prime (11221120121) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 45438 + ... + 156546.

It is an arithmetic number, because the mean of its divisors is an integer number (467495325).

Almost surely, 2^11221120128 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 11221120128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14959850400).

11221120128 is an abundant number, since it is smaller than the sum of its proper divisors (18698580672).

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

11221120128 is a wasteful number, since it uses less digits than its factorization.

11221120128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111389 (or 111377 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 21.

Adding to 11221120128 its reverse (82102112211), we get a palindrome (93323232339).

The spelling of 11221120128 in words is "eleven billion, two hundred twenty-one million, one hundred twenty thousand, one hundred twenty-eight".