20121233220 has 96 divisors (see below), whose sum is σ = 68290266240. Its totient is φ = 4877873280.

The previous prime is 20121233191. The next prime is 20121233233. The reversal of 20121233220 is 2233212102.

20121233220 is a `hidden beast` number, since 201 + 212 + 33 + 220 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 20121233193 and 20121233202.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1687767 + ... + 1699646.

It is an arithmetic number, because the mean of its divisors is an integer number (711356940).

Almost surely, 2^20121233220 is an apocalyptic number.

20121233220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20121233220 is an abundant number, since it is smaller than the sum of its proper divisors (48169033020).

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

20121233220 is a wasteful number, since it uses less digits than its factorization.

20121233220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3387442 (or 3387434 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

Adding to 20121233220 its reverse (2233212102), we get a palindrome (22354445322).

It can be divided in two parts, 201212 and 33220, that added together give a palindrome (234432).

The spelling of 20121233220 in words is "twenty billion, one hundred twenty-one million, two hundred thirty-three thousand, two hundred twenty".