1221222111021 has 24 divisors (see below), whose sum is σ = 1939039708320. Its totient is φ = 734484722400.

The previous prime is 1221222111007. The next prime is 1221222111059. The reversal of 1221222111021 is 1201112221221.

It is not a de Polignac number, because 1221222111021 - 2¹⁷ = 1221221979949 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1221222110985 and 1221222111003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221222111071) 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 23 ways as a sum of consecutive naturals, for example, 47069386 + ... + 47095323.

It is an arithmetic number, because the mean of its divisors is an integer number (80793321180).

Almost surely, 2^{1221222111021} is an apocalyptic number.

1221222111021 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1221222111021 is a deficient number, since it is larger than the sum of its proper divisors (717817597299).

1221222111021 is a wasteful number, since it uses less digits than its factorization.

1221222111021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94164857 (or 94164854 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 1221222111021 its reverse (1201112221221), we get a palindrome (2422334332242).

The spelling of 1221222111021 in words is "one trillion, two hundred twenty-one billion, two hundred twenty-two million, one hundred eleven thousand, twenty-one".