111997728 has 84 divisors (see below), whose sum is σ = 330660918. Its totient is φ = 37324800.

The previous prime is 111997693. The next prime is 111997729. The reversal of 111997728 is 827799111.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 92390544 + 19607184 = 9612^2 + 4428^2 .

It is not an unprimeable number, because it can be changed into a prime (111997729) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 13 ways as a sum of consecutive naturals, for example, 20928 + ... + 25728.

Almost surely, 2^111997728 is an apocalyptic number.

111997728 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 111997728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (165330459).

111997728 is an abundant number, since it is smaller than the sum of its proper divisors (218663190).

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

111997728 is an frugal number, since it uses more digits than its factorization.

111997728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4829 (or 4806 counting only the distinct ones).

The product of its digits is 63504, while the sum is 45.

The square root of 111997728 is about 10582.8979018036. The cubic root of 111997728 is about 482.0251933825.

The spelling of 111997728 in words is "one hundred eleven million, nine hundred ninety-seven thousand, seven hundred twenty-eight".