1220121233221 has 4 divisors (see below), whose sum is σ = 1331041345344. Its totient is φ = 1109201121100.

The previous prime is 1220121233207. The next prime is 1220121233237. The reversal of 1220121233221 is 1223321210221.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1220121233221 - 2⁹ = 1220121232709 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1220121233192 and 1220121233201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1220121233251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 55460056045 + ... + 55460056066.

It is an arithmetic number, because the mean of its divisors is an integer number (332760336336).

Almost surely, 2^{1220121233221} is an apocalyptic number.

1220121233221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1220121233221 is a deficient number, since it is larger than the sum of its proper divisors (110920112123).

1220121233221 is a wasteful number, since it uses less digits than its factorization.

1220121233221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110920112122.

The product of its (nonzero) digits is 576, while the sum is 22.

Adding to 1220121233221 its reverse (1223321210221), we get a palindrome (2443442443442).

The spelling of 1220121233221 in words is "one trillion, two hundred twenty billion, one hundred twenty-one million, two hundred thirty-three thousand, two hundred twenty-one".