111689728 has 60 divisors (see below), whose sum is σ = 237102012. Its totient is φ = 52428800.

The previous prime is 111689723. The next prime is 111689761. The reversal of 111689728 is 827986111.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 102252544 + 9437184 = 10112^2 + 3072^2 .

It is not an unprimeable number, because it can be changed into a prime (111689723) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 278328 + ... + 278728.

Almost surely, 2^111689728 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 111689728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (118551006).

111689728 is an abundant number, since it is smaller than the sum of its proper divisors (125412284).

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

111689728 is an frugal number, since it uses more digits than its factorization.

111689728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 446 (or 420 counting only the distinct ones).

The product of its digits is 48384, while the sum is 43.

The square root of 111689728 is about 10568.3361036636. The cubic root of 111689728 is about 481.5829223202.

The spelling of 111689728 in words is "one hundred eleven million, six hundred eighty-nine thousand, seven hundred twenty-eight".