1221210112122 has 288 divisors, whose sum is σ = 3668701196160. Its totient is φ = 284882158080.

The previous prime is 1221210112121. The next prime is 1221210112127. The reversal of 1221210112122 is 2212110121221.

1221210112122 is a `hidden beast` number, since 1 + 221 + 210 + 112 + 122 = 666.

It is a super-2 number, since 2×1221210112122² (a number of 25 digits) contains 22 as substring.

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 = 1221210112095 and 1221210112104.

It is not an unprimeable number, because it can be changed into a prime (1221210112121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 8596204 + ... + 8737112.

It is an arithmetic number, because the mean of its divisors is an integer number (12738545820).

Almost surely, 2^{1221210112122} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1221210112122, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1834350598080).

1221210112122 is an abundant number, since it is smaller than the sum of its proper divisors (2447491084038).

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

1221210112122 is a wasteful number, since it uses less digits than its factorization.

1221210112122 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140998 (or 140982 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 1221210112122 its reverse (2212110121221), we get a palindrome (3433320233343).

Subtracting 1221210112122 from its reverse (2212110121221), we obtain a palindrome (990900009099).

The spelling of 1221210112122 in words is "one trillion, two hundred twenty-one billion, two hundred ten million, one hundred twelve thousand, one hundred twenty-two".