1121728356 has 72 divisors (see below), whose sum is σ = 3255243264. Its totient is φ = 319040640.

The previous prime is 1121728351. The next prime is 1121728369. The reversal of 1121728356 is 6538271211.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 1121728356.

It is not an unprimeable number, because it can be changed into a prime (1121728351) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 46216 + ... + 66176.

It is an arithmetic number, because the mean of its divisors is an integer number (45211712).

Almost surely, 2^1121728356 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 1121728356, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1627621632).

1121728356 is an abundant number, since it is smaller than the sum of its proper divisors (2133514908).

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

1121728356 is a wasteful number, since it uses less digits than its factorization.

1121728356 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20201 (or 20196 counting only the distinct ones).

The product of its digits is 20160, while the sum is 36.

The square root of 1121728356 is about 33492.2133637059. The cubic root of 1121728356 is about 1039.0327409591.

Adding to 1121728356 its reverse (6538271211), we get a palindrome (7659999567).

The spelling of 1121728356 in words is "one billion, one hundred twenty-one million, seven hundred twenty-eight thousand, three hundred fifty-six".