1221220121222 has 4 divisors (see below), whose sum is σ = 1831830181836. Its totient is φ = 610610060610.

The previous prime is 1221220121221. The next prime is 1221220121239. The reversal of 1221220121222 is 2221210221221.

It is a semiprime because it is the product of two primes.

It is a junction number, because it is equal to n+sod(n) for n = 1221220121194 and 1221220121203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221220121221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 305305030304 + ... + 305305030307.

It is an arithmetic number, because the mean of its divisors is an integer number (457957545459).

Almost surely, 2^{1221220121222} is an apocalyptic number.

1221220121222 is a deficient number, since it is larger than the sum of its proper divisors (610610060614).

1221220121222 is an equidigital number, since it uses as much as digits as its factorization.

1221220121222 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 610610060613.

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

Adding to 1221220121222 its reverse (2221210221221), we get a palindrome (3442430342443).

Subtracting 1221220121222 from its reverse (2221210221221), we obtain a palindrome (999990099999).

The spelling of 1221220121222 in words is "one trillion, two hundred twenty-one billion, two hundred twenty million, one hundred twenty-one thousand, two hundred twenty-two".