111221100 has 216 divisors, whose sum is σ = 379142400. Its totient is φ = 28226880.

The previous prime is 111221057. The next prime is 111221101. The reversal of 111221100 is 1122111.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a zygodrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (111221101) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 558801 + ... + 558999.

Almost surely, 2^111221100 is an apocalyptic number.

111221100 is a gapful number since it is divisible by the number (10) 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 111221100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (189571200).

111221100 is an abundant number, since it is smaller than the sum of its proper divisors (267921300).

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

111221100 is a wasteful number, since it uses less digits than its factorization.

111221100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 251 (or 232 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

The square root of 111221100 is about 10546.1414744920. The cubic root of 111221100 is about 480.9084358826.

Adding to 111221100 its reverse (1122111), we get a palindrome (112343211).

The spelling of 111221100 in words is "one hundred eleven million, two hundred twenty-one thousand, one hundred".