11564121728 has 128 divisors (see below), whose sum is σ = 24091992000. Its totient is φ = 5525757952.

The previous prime is 11564121727. The next prime is 11564121739. The reversal of 11564121728 is 82712146511.

It is a tau number, because it is divible by the number of its divisors (128).

It is a super-2 number, since 2×11564121728² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 11564121691 and 11564121700.

It is not an unprimeable number, because it can be changed into a prime (11564121727) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 64603943 + ... + 64604121.

Almost surely, 2^11564121728 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 11564121728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12045996000).

11564121728 is an abundant number, since it is smaller than the sum of its proper divisors (12527870272).

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

11564121728 is a wasteful number, since it uses less digits than its factorization.

11564121728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 442 (or 430 counting only the distinct ones).

The product of its digits is 26880, while the sum is 38.

The spelling of 11564121728 in words is "eleven billion, five hundred sixty-four million, one hundred twenty-one thousand, seven hundred twenty-eight".