20112121220 has 12 divisors (see below), whose sum is σ = 42235454604. Its totient is φ = 8044848480.

The previous prime is 20112121189. The next prime is 20112121229. The reversal of 20112121220 is 2212121102.

It can be written as a sum of positive squares in 2 ways, for example, as 10801029184 + 9311092036 = 103928^2 + 96494^2 .

It is a junction number, because it is equal to n+sod(n) for n = 20112121195 and 20112121204.

It is not an unprimeable number, because it can be changed into a prime (20112121229) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 502803011 + ... + 502803050.

It is an arithmetic number, because the mean of its divisors is an integer number (3519621217).

Almost surely, 2^20112121220 is an apocalyptic number.

20112121220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20112121220 is an abundant number, since it is smaller than the sum of its proper divisors (22123333384).

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

20112121220 is a wasteful number, since it uses less digits than its factorization.

20112121220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1005606070 (or 1005606068 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 20112121220 its reverse (2212121102), we get a palindrome (22324242322).

The spelling of 20112121220 in words is "twenty billion, one hundred twelve million, one hundred twenty-one thousand, two hundred twenty".