1221100111222 has 16 divisors (see below), whose sum is σ = 1876364037072. Its totient is φ = 595646058880.

The previous prime is 1221100111123. The next prime is 1221100111229. The reversal of 1221100111222 is 2221110011221.

It is a junction number, because it is equal to n+sod(n) for n = 1221100111196 and 1221100111205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221100111229) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4663578 + ... + 4918450.

It is an arithmetic number, because the mean of its divisors is an integer number (117272752317).

Almost surely, 2^{1221100111222} is an apocalyptic number.

1221100111222 is a deficient number, since it is larger than the sum of its proper divisors (655263925850).

1221100111222 is a wasteful number, since it uses less digits than its factorization.

1221100111222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 313343.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 1221100111222 its reverse (2221110011221), we get a palindrome (3442210122443).

The spelling of 1221100111222 in words is "one trillion, two hundred twenty-one billion, one hundred million, one hundred eleven thousand, two hundred twenty-two".