1221220212212 has 48 divisors (see below), whose sum is σ = 2869440508032. Its totient is φ = 439200074880.

The previous prime is 1221220212211. The next prime is 1221220212257. The reversal of 1221220212212 is 2122120221221.

It is a super-4 number, since 4×1221220212212⁴ (a number of 49 digits) contains 4444 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221220212211) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 152496023 + ... + 152504030.

It is an arithmetic number, because the mean of its divisors is an integer number (59780010584).

Almost surely, 2^{1221220212212} is an apocalyptic number.

It is an amenable number.

1221220212212 is an abundant number, since it is smaller than the sum of its proper divisors (1648220295820).

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

1221220212212 is a wasteful number, since it uses less digits than its factorization.

1221220212212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 305000088 (or 305000086 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 20.

Adding to 1221220212212 its reverse (2122120221221), we get a palindrome (3343340433433).

Subtracting 1221220212212 from its reverse (2122120221221), we obtain a palindrome (900900009009).

The spelling of 1221220212212 in words is "one trillion, two hundred twenty-one billion, two hundred twenty million, two hundred twelve thousand, two hundred twelve".