111421128 has 128 divisors (see below), whose sum is σ = 363121920. Its totient is φ = 27648000.

The previous prime is 111421091. The next prime is 111421139. The reversal of 111421128 is 821124111.

It is a super-3 number, since 3×111421128³ (a number of 25 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 35628 + ... + 38628.

It is an arithmetic number, because the mean of its divisors is an integer number (2836890).

Almost surely, 2^111421128 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 111421128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (181560960).

111421128 is an abundant number, since it is smaller than the sum of its proper divisors (251700792).

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

111421128 is a wasteful number, since it uses less digits than its factorization.

111421128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3047 (or 3043 counting only the distinct ones).

The product of its digits is 128, while the sum is 21.

The square root of 111421128 is about 10555.6206828400. The cubic root of 111421128 is about 481.1965632915.

Adding to 111421128 its reverse (821124111), we get a palindrome (932545239).

The spelling of 111421128 in words is "one hundred eleven million, four hundred twenty-one thousand, one hundred twenty-eight".