115561728 has 90 divisors (see below), whose sum is σ = 344645994. Its totient is φ = 38513664.

The previous prime is 115561727. The next prime is 115561759. The reversal of 115561728 is 827165511.

115561728 is a `hidden beast` number, since 1 + 15 + 5 + 617 + 28 = 666.

It can be written as a sum of positive squares in only one way, i.e., 69755904 + 45805824 = 8352^2 + 6768^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 115561692 and 115561701.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (115561727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 17950 + ... + 23522.

Almost surely, 2^115561728 is an apocalyptic number.

115561728 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 115561728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (172322997).

115561728 is an abundant number, since it is smaller than the sum of its proper divisors (229084266).

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

115561728 is an frugal number, since it uses more digits than its factorization.

115561728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5601 (or 5578 counting only the distinct ones).

The product of its digits is 16800, while the sum is 36.

The square root of 115561728 is about 10749.9640929633. The cubic root of 115561728 is about 487.0849105713.

The spelling of 115561728 in words is "one hundred fifteen million, five hundred sixty-one thousand, seven hundred twenty-eight".