1211000221121 has 4 divisors (see below), whose sum is σ = 1263652404672. Its totient is φ = 1158348037572.

The previous prime is 1211000221033. The next prime is 1211000221133. The reversal of 1211000221121 is 1211220001121.

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 a de Polignac number, because none of the positive numbers 2^k-1211000221121 is a prime.

It is a super-2 number, since 2×1211000221121² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1211000221096 and 1211000221105.

It is not an unprimeable number, because it can be changed into a prime (1211000221021) 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 3 ways as a sum of consecutive naturals, for example, 26326091741 + ... + 26326091786.

It is an arithmetic number, because the mean of its divisors is an integer number (315913101168).

Almost surely, 2^{1211000221121} is an apocalyptic number.

It is an amenable number.

1211000221121 is a deficient number, since it is larger than the sum of its proper divisors (52652183551).

1211000221121 is an equidigital number, since it uses as much as digits as its factorization.

1211000221121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52652183550.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 1211000221121 its reverse (1211220001121), we get a palindrome (2422220222242).

The spelling of 1211000221121 in words is "one trillion, two hundred eleven billion, two hundred twenty-one thousand, one hundred twenty-one".