1221310211121 has 160 divisors (see below), whose sum is σ = 2459699708928. Its totient is φ = 585633810240.

The previous prime is 1221310211101. The next prime is 1221310211137. The reversal of 1221310211121 is 1211120131221.

It is a happy number.

1221310211121 is a `hidden beast` number, since 1 + 2 + 21 + 310 + 211 + 121 = 666.

It is not a de Polignac number, because 1221310211121 - 2⁹ = 1221310210609 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1221310211094 and 1221310211103.

It is not an unprimeable number, because it can be changed into a prime (1221310211101) 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 159 ways as a sum of consecutive naturals, for example, 19671690 + ... + 19733676.

Almost surely, 2^{1221310211121} is an apocalyptic number.

1221310211121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1221310211121 is an abundant number, since it is smaller than the sum of its proper divisors (1238389497807).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1221310211121 is an frugal number, since it uses more digits than its factorization.

1221310211121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62045 (or 62021 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 18.

Adding to 1221310211121 its reverse (1211120131221), we get a palindrome (2432430342342).

The spelling of 1221310211121 in words is "one trillion, two hundred twenty-one billion, three hundred ten million, two hundred eleven thousand, one hundred twenty-one".