1221221111222 has 16 divisors (see below), whose sum is σ = 2099846752512. Its totient is φ = 521799264360.

The previous prime is 1221221111207. The next prime is 1221221111239. The reversal of 1221221111222 is 2221111221221.

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

It is a junction number, because it is equal to n+sod(n) for n = 1221221111194 and 1221221111203.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 131762858 + ... + 131772125.

It is an arithmetic number, because the mean of its divisors is an integer number (131240422032).

Almost surely, 2^{1221221111222} is an apocalyptic number.

1221221111222 is a deficient number, since it is larger than the sum of its proper divisors (878625641290).

1221221111222 is a wasteful number, since it uses less digits than its factorization.

1221221111222 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 263535323.

The product of its digits is 128, while the sum is 20.

Adding to 1221221111222 its reverse (2221111221221), we get a palindrome (3442332332443).

The spelling of 1221221111222 in words is "one trillion, two hundred twenty-one billion, two hundred twenty-one million, one hundred eleven thousand, two hundred twenty-two".