1211011220121 has 16 divisors (see below), whose sum is σ = 1615959414720. Its totient is φ = 806702172480.

The previous prime is 1211011220113. The next prime is 1211011220143. The reversal of 1211011220121 is 1210221101121.

It is a happy number.

It is not a de Polignac number, because 1211011220121 - 2³ = 1211011220113 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1211011220121.

It is not an unprimeable number, because it can be changed into a prime (1211011220171) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20903631 + ... + 20961483.

It is an arithmetic number, because the mean of its divisors is an integer number (100997463420).

Almost surely, 2^{1211011220121} is an apocalyptic number.

It is an amenable number.

1211011220121 is a deficient number, since it is larger than the sum of its proper divisors (404948194599).

1211011220121 is a wasteful number, since it uses less digits than its factorization.

1211011220121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63256.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 1211011220121 its reverse (1210221101121), we get a palindrome (2421232321242).

The spelling of 1211011220121 in words is "one trillion, two hundred eleven billion, eleven million, two hundred twenty thousand, one hundred twenty-one".