1211020221121 has 4 divisors (see below), whose sum is σ = 1211060273200. Its totient is φ = 1210980169044.

The previous prime is 1211020221041. The next prime is 1211020221127. The reversal of 1211020221121 is 1211220201121.

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 1211020221121 - 2¹⁹ = 1211019696833 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1211020221095 and 1211020221104.

It is not an unprimeable number, because it can be changed into a prime (1211020221127) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19980651 + ... + 20041168.

It is an arithmetic number, because the mean of its divisors is an integer number (302765068300).

Almost surely, 2^{1211020221121} is an apocalyptic number.

It is an amenable number.

1211020221121 is a deficient number, since it is larger than the sum of its proper divisors (40052079).

1211020221121 is an equidigital number, since it uses as much as digits as its factorization.

1211020221121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40052078.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 1211020221121 its reverse (1211220201121), we get a palindrome (2422240422242).

The spelling of 1211020221121 in words is "one trillion, two hundred eleven billion, twenty million, two hundred twenty-one thousand, one hundred twenty-one".