1221100332221 has 16 divisors (see below), whose sum is σ = 1523661874560. Its totient is φ = 950724833280.

The previous prime is 1221100332191. The next prime is 1221100332223. The reversal of 1221100332221 is 1222330011221.

It is a cyclic number.

It is not a de Polignac number, because 1221100332221 - 2²² = 1221096137917 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1221100332193 and 1221100332202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221100332223) 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 15 ways as a sum of consecutive naturals, for example, 6421676 + ... + 6609093.

It is an arithmetic number, because the mean of its divisors is an integer number (95228867160).

Almost surely, 2^{1221100332221} is an apocalyptic number.

1221100332221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1221100332221 is a deficient number, since it is larger than the sum of its proper divisors (302561542339).

1221100332221 is a wasteful number, since it uses less digits than its factorization.

1221100332221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13032004.

The product of its (nonzero) digits is 288, while the sum is 20.

Adding to 1221100332221 its reverse (1222330011221), we get a palindrome (2443430343442).

The spelling of 1221100332221 in words is "one trillion, two hundred twenty-one billion, one hundred million, three hundred thirty-two thousand, two hundred twenty-one".