1221212211222 has 16 divisors (see below), whose sum is σ = 2442524736960. Its totient is φ = 407054017992.

The previous prime is 1221212211221. The next prime is 1221212211251. The reversal of 1221212211222 is 2221122121221.

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 (1221212211221) 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 7 ways as a sum of consecutive naturals, for example, 4021048 + ... + 4314075.

It is an arithmetic number, because the mean of its divisors is an integer number (152657796060).

Almost surely, 2^{1221212211222} is an apocalyptic number.

1221212211222 is an abundant number, since it is smaller than the sum of its proper divisors (1221312525738).

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

1221212211222 is a wasteful number, since it uses less digits than its factorization.

1221212211222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8359547.

The product of its digits is 256, while the sum is 21.

Adding to 1221212211222 its reverse (2221122121221), we get a palindrome (3442334332443).

Subtracting 1221212211222 from its reverse (2221122121221), we obtain a palindrome (999909909999).

The spelling of 1221212211222 in words is "one trillion, two hundred twenty-one billion, two hundred twelve million, two hundred eleven thousand, two hundred twenty-two".