1131605728 has 48 divisors (see below), whose sum is σ = 2440730880. Its totient is φ = 512176000.

The previous prime is 1131605711. The next prime is 1131605729. The reversal of 1131605728 is 8275061311.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 1131605693 and 1131605702.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1131605729) 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, 77403 + ... + 90853.

It is an arithmetic number, because the mean of its divisors is an integer number (50848560).

Almost surely, 2^1131605728 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 1131605728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1220365440).

1131605728 is an abundant number, since it is smaller than the sum of its proper divisors (1309125152).

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

1131605728 is a wasteful number, since it uses less digits than its factorization.

1131605728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13711 (or 13703 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 34.

The square root of 1131605728 is about 33639.3479128238. The cubic root of 1131605728 is about 1042.0735651217.

The spelling of 1131605728 in words is "one billion, one hundred thirty-one million, six hundred five thousand, seven hundred twenty-eight".