13381220 has 24 divisors (see below), whose sum is σ = 28212408. Its totient is φ = 5331200.

The previous prime is 13381217. The next prime is 13381231. The reversal of 13381220 is 2218331.

It can be written as a sum of positive squares in 4 ways, for example, as 14884 + 13366336 = 122^2 + 3656^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 13381192 and 13381201.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4430 + ... + 6810.

It is an arithmetic number, because the mean of its divisors is an integer number (1175517).

Almost surely, 2^13381220 is an apocalyptic number.

13381220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

13381220 is an abundant number, since it is smaller than the sum of its proper divisors (14831188).

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

13381220 is a wasteful number, since it uses less digits than its factorization.

13381220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2671 (or 2669 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 13381220 is about 3658.0349916314. The cubic root of 13381220 is about 237.4097607313.

Adding to 13381220 its reverse (2218331), we get a palindrome (15599551).

The spelling of 13381220 in words is "thirteen million, three hundred eighty-one thousand, two hundred twenty".