1021121221221 has 24 divisors (see below), whose sum is σ = 1476250651200. Its totient is φ = 680148760896.

The previous prime is 1021121221189. The next prime is 1021121221259. The reversal of 1021121221221 is 1221221211201.

1021121221221 is a `hidden beast` number, since 1 + 0 + 211 + 212 + 21 + 221 = 666.

It is not a de Polignac number, because 1021121221221 - 2⁵ = 1021121221189 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1021121221194 and 1021121221203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1021121221721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 68144496 + ... + 68159478.

It is an arithmetic number, because the mean of its divisors is an integer number (61510443800).

Almost surely, 2^{1021121221221} is an apocalyptic number.

It is an amenable number.

1021121221221 is a deficient number, since it is larger than the sum of its proper divisors (455129429979).

1021121221221 is a wasteful number, since it uses less digits than its factorization.

1021121221221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21145 (or 21142 counting only the distinct ones).

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

Adding to 1021121221221 its reverse (1221221211201), we get a palindrome (2242342432422).

The spelling of 1021121221221 in words is "one trillion, twenty-one billion, one hundred twenty-one million, two hundred twenty-one thousand, two hundred twenty-one".