12221100 has 108 divisors (see below), whose sum is σ = 39448864. Its totient is φ = 3162240.

The previous prime is 12221089. The next prime is 12221107. The reversal of 12221100 is 112221.

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

It is not an unprimeable number, because it can be changed into a prime (12221107) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 33117 + ... + 33483.

Almost surely, 2^12221100 is an apocalyptic number.

12221100 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 12221100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19724432).

12221100 is an abundant number, since it is smaller than the sum of its proper divisors (27227764).

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

12221100 is a wasteful number, since it uses less digits than its factorization.

12221100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 424 (or 414 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

The square root of 12221100 is about 3495.8689906803. The cubic root of 12221100 is about 230.3403907568.

Adding to 12221100 its reverse (112221), we get a palindrome (12333321).

It can be divided in two parts, 12221 and 100, that added together give a palindrome (12321).

The spelling of 12221100 in words is "twelve million, two hundred twenty-one thousand, one hundred".