12211820 has 48 divisors (see below), whose sum is σ = 26611200. Its totient is φ = 4704960.

The previous prime is 12211819. The next prime is 12211841. The reversal of 12211820 is 2811221.

It is a happy number.

It is a congruent number.

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 15 ways as a sum of consecutive naturals, for example, 93155 + ... + 93285.

It is an arithmetic number, because the mean of its divisors is an integer number (554400).

Almost surely, 2^12211820 is an apocalyptic number.

12211820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12211820 is an abundant number, since it is smaller than the sum of its proper divisors (14399380).

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

12211820 is a wasteful number, since it uses less digits than its factorization.

12211820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 278 (or 276 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 17.

The square root of 12211820 is about 3494.5414577595. The cubic root of 12211820 is about 230.2820735813.

It can be divided in two parts, 12211 and 820, that added together give a palindrome (13031).

The spelling of 12211820 in words is "twelve million, two hundred eleven thousand, eight hundred twenty".