11818820 has 48 divisors (see below), whose sum is σ = 27010368. Its totient is φ = 4318080.

The previous prime is 11818819. The next prime is 11818823. The reversal of 11818820 is 2881811.

11818820 = 394² + 395² + ... + 458².

It is not an unprimeable number, because it can be changed into a prime (11818823) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 33887 + ... + 34233.

It is an arithmetic number, because the mean of its divisors is an integer number (562716).

Almost surely, 2^11818820 is an apocalyptic number.

11818820 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 11818820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13505184).

11818820 is an abundant number, since it is smaller than the sum of its proper divisors (15191548).

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

11818820 is a wasteful number, since it uses less digits than its factorization.

11818820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 500 (or 498 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 29.

The square root of 11818820 is about 3437.8510729815. The cubic root of 11818820 is about 227.7847820350.

Adding to 11818820 its product of nonzero digits (1024), we get a square (11819844 = 3438²).

It can be divided in two parts, 1181 and 8820, that added together give a palindrome (10001).

The spelling of 11818820 in words is "eleven million, eight hundred eighteen thousand, eight hundred twenty".