21121221220112 has 20 divisors (see below), whose sum is σ = 44070240430860. Its totient is φ = 9748255947648.

The previous prime is 21121221220091. The next prime is 21121221220163. The reversal of 21121221220112 is 21102212212112.

It can be written as a sum of positive squares in 2 ways, for example, as 7206411394576 + 13914809825536 = 2684476^2 + 3730256^2 .

It is a super-2 number, since 2×21121221220112² (a number of 27 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 50772166187 + ... + 50772166602.

It is an arithmetic number, because the mean of its divisors is an integer number (2203512021543).

Almost surely, 2^{21121221220112} is an apocalyptic number.

It is an amenable number.

21121221220112 is an abundant number, since it is smaller than the sum of its proper divisors (22949019210748).

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

21121221220112 is a wasteful number, since it uses less digits than its factorization.

21121221220112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101544332810 (or 101544332804 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 20.

Adding to 21121221220112 its reverse (21102212212112), we get a palindrome (42223433432224).

The spelling of 21121221220112 in words is "twenty-one trillion, one hundred twenty-one billion, two hundred twenty-one million, two hundred twenty thousand, one hundred twelve".