1211001220121 has 16 divisors (see below), whose sum is σ = 1510075008000. Its totient is φ = 943477748880.

The previous prime is 1211001220109. The next prime is 1211001220157. The reversal of 1211001220121 is 1210221001121.

It is a cyclic number.

It is not a de Polignac number, because 1211001220121 - 2¹⁰ = 1211001219097 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1211001220096 and 1211001220105.

It is not an unprimeable number, because it can be changed into a prime (1211001220421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 870371 + ... + 1783128.

It is an arithmetic number, because the mean of its divisors is an integer number (94379688000).

Almost surely, 2^{1211001220121} is an apocalyptic number.

1211001220121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1211001220121 is a deficient number, since it is larger than the sum of its proper divisors (299073787879).

1211001220121 is a wasteful number, since it uses less digits than its factorization.

1211001220121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2659444.

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

Adding to 1211001220121 its reverse (1210221001121), we get a palindrome (2421222221242).

The spelling of 1211001220121 in words is "one trillion, two hundred eleven billion, one million, two hundred twenty thousand, one hundred twenty-one".