111221660 has 48 divisors (see below), whose sum is σ = 257910912. Its totient is φ = 39950400.

The previous prime is 111221657. The next prime is 111221681. The reversal of 111221660 is 66122111.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 15215 + ... + 21305.

It is an arithmetic number, because the mean of its divisors is an integer number (5373144).

Almost surely, 2^111221660 is an apocalyptic number.

111221660 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 111221660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (128955456).

111221660 is an abundant number, since it is smaller than the sum of its proper divisors (146689252).

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

111221660 is a wasteful number, since it uses less digits than its factorization.

111221660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6194 (or 6192 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 20.

The square root of 111221660 is about 10546.1680244532. The cubic root of 111221660 is about 480.9092430084.

Adding to 111221660 its reverse (66122111), we get a palindrome (177343771).

The spelling of 111221660 in words is "one hundred eleven million, two hundred twenty-one thousand, six hundred sixty".