1221121121211 has 8 divisors (see below), whose sum is σ = 1809068327760. Its totient is φ = 814080747456.

The previous prime is 1221121121153. The next prime is 1221121121237. The reversal of 1221121121211 is 1121211211221.

It is a happy number.

1221121121211 is a `hidden beast` number, since 1 + 221 + 1 + 211 + 21 + 211 = 666.

It is not a de Polignac number, because 1221121121211 - 2⁶ = 1221121121147 is a prime.

It is a super-2 number, since 2×1221121121211² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1221121121251) 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 7 ways as a sum of consecutive naturals, for example, 22613354070 + ... + 22613354123.

It is an arithmetic number, because the mean of its divisors is an integer number (226133540970).

Almost surely, 2^{1221121121211} is an apocalyptic number.

1221121121211 is a deficient number, since it is larger than the sum of its proper divisors (587947206549).

1221121121211 is an equidigital number, since it uses as much as digits as its factorization.

1221121121211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45226708202 (or 45226708196 counting only the distinct ones).

The product of its digits is 32, while the sum is 18.

Adding to 1221121121211 its reverse (1121211211221), we get a palindrome (2342332332432).

The spelling of 1221121121211 in words is "one trillion, two hundred twenty-one billion, one hundred twenty-one million, one hundred twenty-one thousand, two hundred eleven".