13321220 has 48 divisors (see below), whose sum is σ = 30796416. Its totient is φ = 4800000.

The previous prime is 13321219. The next prime is 13321229. The reversal of 13321220 is 2212331.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 13321195 and 13321204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13321229) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33020 + ... + 33420.

It is an arithmetic number, because the mean of its divisors is an integer number (641592).

Almost surely, 2^13321220 is an apocalyptic number.

13321220 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 13321220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15398208).

13321220 is an abundant number, since it is smaller than the sum of its proper divisors (17475196).

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

13321220 is a wasteful number, since it uses less digits than its factorization.

13321220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 572 (or 570 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 14.

The square root of 13321220 is about 3649.8246533224. The cubic root of 13321220 is about 237.0543888183.

Adding to 13321220 its reverse (2212331), we get a palindrome (15533551).

Subtracting from 13321220 its reverse (2212331), we obtain a square (11108889 = 3333²).

It can be divided in two parts, 1332 and 1220, that added together give a palindrome (2552).

The spelling of 13321220 in words is "thirteen million, three hundred twenty-one thousand, two hundred twenty".