1221221021212 has 12 divisors (see below), whose sum is σ = 2161149560640. Its totient is φ = 603749718176.

The previous prime is 1221221021173. The next prime is 1221221021219. The reversal of 1221221021212 is 2121201221221.

It is a self number, because there is not a number n which added to its sum of digits gives 1221221021212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221221021219) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1715197708 + ... + 1715198419.

It is an arithmetic number, because the mean of its divisors is an integer number (180095796720).

Almost surely, 2^{1221221021212} is an apocalyptic number.

It is an amenable number.

1221221021212 is a deficient number, since it is larger than the sum of its proper divisors (939928539428).

1221221021212 is a wasteful number, since it uses less digits than its factorization.

1221221021212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3430396220 (or 3430396218 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 1221221021212 its reverse (2121201221221), we get a palindrome (3342422242433).

The spelling of 1221221021212 in words is "one trillion, two hundred twenty-one billion, two hundred twenty-one million, twenty-one thousand, two hundred twelve".