1221212243412 has 144 divisors (see below), whose sum is σ = 3573540006400. Its totient is φ = 344466053568.

The previous prime is 1221212243399. The next prime is 1221212243413. The reversal of 1221212243412 is 2143422121221.

1221212243412 is a `hidden beast` number, since 1 + 2 + 2 + 1 + 2 + 1 + 2 + 243 + 412 = 666.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221212243413) 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 47 ways as a sum of consecutive naturals, for example, 124240914 + ... + 124250742.

Almost surely, 2^{1221212243412} is an apocalyptic number.

1221212243412 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1221212243412, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1786770003200).

1221212243412 is an abundant number, since it is smaller than the sum of its proper divisors (2352327762988).

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

1221212243412 is an frugal number, since it uses more digits than its factorization.

1221212243412 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10083 (or 9920 counting only the distinct ones).

The product of its digits is 3072, while the sum is 27.

Adding to 1221212243412 its reverse (2143422121221), we get a palindrome (3364634364633).

The spelling of 1221212243412 in words is "one trillion, two hundred twenty-one billion, two hundred twelve million, two hundred forty-three thousand, four hundred twelve".