1211001222121 has 4 divisors (see below), whose sum is σ = 1211051576644. Its totient is φ = 1210950867600.

The previous prime is 1211001222097. The next prime is 1211001222163. The reversal of 1211001222121 is 1212221001121.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1208064774400 + 2936447721 = 1099120^2 + 54189^2 .

It is a cyclic number.

It is not a de Polignac number, because 1211001222121 - 2¹⁵ = 1211001189353 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1211001222095 and 1211001222104.

It is not an unprimeable number, because it can be changed into a prime (1211001223121) 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, 25141170 + ... + 25189291.

It is an arithmetic number, because the mean of its divisors is an integer number (302762894161).

Almost surely, 2^{1211001222121} is an apocalyptic number.

It is an amenable number.

1211001222121 is a deficient number, since it is larger than the sum of its proper divisors (50354523).

1211001222121 is an equidigital number, since it uses as much as digits as its factorization.

1211001222121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50354522.

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

Adding to 1211001222121 its reverse (1212221001121), we get a palindrome (2423222223242).

The spelling of 1211001222121 in words is "one trillion, two hundred eleven billion, one million, two hundred twenty-two thousand, one hundred twenty-one".