13221100 has 72 divisors (see below), whose sum is σ = 30623040. Its totient is φ = 4945920.

The previous prime is 13221083. The next prime is 13221101. The reversal of 13221100 is 112231.

13221100 = T₁₄₄ + T₁₄₅ + ... + T₄₃₄.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is not an unprimeable number, because it can be changed into a prime (13221101) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 136252 + ... + 136348.

It is an arithmetic number, because the mean of its divisors is an integer number (425320).

Almost surely, 2^13221100 is an apocalyptic number.

13221100 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 13221100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15311520).

13221100 is an abundant number, since it is smaller than the sum of its proper divisors (17401940).

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

13221100 is a wasteful number, since it uses less digits than its factorization.

13221100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 187 (or 180 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 10.

The square root of 13221100 is about 3636.0830573572. The cubic root of 13221100 is about 236.4590080432.

Adding to 13221100 its reverse (112231), we get a palindrome (13333331).

The spelling of 13221100 in words is "thirteen million, two hundred twenty-one thousand, one hundred".