13221516 has 96 divisors (see below), whose sum is σ = 39513600. Its totient is φ = 3340800.

The previous prime is 13221503. The next prime is 13221553. The reversal of 13221516 is 61512231.

13221516 = 55² + 56² + ... + 341².

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

It is a junction number, because it is equal to n+sod(n) for n = 13221492 and 13221501.

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 31 ways as a sum of consecutive naturals, for example, 37710 + ... + 38058.

It is an arithmetic number, because the mean of its divisors is an integer number (411600).

Almost surely, 2^13221516 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 13221516, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19756800).

13221516 is an abundant number, since it is smaller than the sum of its proper divisors (26292084).

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

13221516 is a wasteful number, since it uses less digits than its factorization.

13221516 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 415 (or 413 counting only the distinct ones).

The product of its digits is 360, while the sum is 21.

The square root of 13221516 is about 3636.1402613211. The cubic root of 13221516 is about 236.4614880667.

Adding to 13221516 its reverse (61512231), we get a palindrome (74733747).

It can be divided in two parts, 132215 and 16, that added together give a palindrome (132231).

The spelling of 13221516 in words is "thirteen million, two hundred twenty-one thousand, five hundred sixteen".