21120121011220 has 144 divisors (see below), whose sum is σ = 59246054320320. Its totient is φ = 6236426649600.

The previous prime is 21120121011083. The next prime is 21120121011221. The reversal of 21120121011220 is 2211012102112.

It is a junction number, because it is equal to n+sod(n) for n = 21120121011194 and 21120121011203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21120121011221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 51352941 + ... + 51762580.

It is an arithmetic number, because the mean of its divisors is an integer number (411430932780).

Almost surely, 2^{21120121011220} is an apocalyptic number.

21120121011220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21120121011220 is an abundant number, since it is smaller than the sum of its proper divisors (38125933309100).

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

21120121011220 is a wasteful number, since it uses less digits than its factorization.

21120121011220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103115574 (or 103115565 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21120121011220 its reverse (2211012102112), we get a palindrome (23331133113332).

The spelling of 21120121011220 in words is "twenty-one trillion, one hundred twenty billion, one hundred twenty-one million, eleven thousand, two hundred twenty".