11381220 has 72 divisors (see below), whose sum is σ = 35203896. Its totient is φ = 2975232.

The previous prime is 11381219. The next prime is 11381221. The reversal of 11381220 is 2218311.

It is an interprime number because it is at equal distance from previous prime (11381219) and next prime (11381221).

It can be written as a sum of positive squares in 4 ways, for example, as 2090916 + 9290304 = 1446^2 + 3048^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a nialpdrome in base 15.

It is a junction number, because it is equal to n+sod(n) for n = 11381193 and 11381202.

It is not an unprimeable number, because it can be changed into a prime (11381221) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 8944 + ... + 10136.

It is an arithmetic number, because the mean of its divisors is an integer number (488943).

Almost surely, 2^11381220 is an apocalyptic number.

11381220 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 11381220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (17601948).

11381220 is an abundant number, since it is smaller than the sum of its proper divisors (23822676).

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

11381220 is a wasteful number, since it uses less digits than its factorization.

11381220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1261 (or 1256 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

The square root of 11381220 is about 3373.6063789363. The cubic root of 11381220 is about 224.9380570226.

Adding to 11381220 its reverse (2218311), we get a palindrome (13599531).

The spelling of 11381220 in words is "eleven million, three hundred eighty-one thousand, two hundred twenty".