1221001122121 has 16 divisors (see below), whose sum is σ = 1345792896000. Its totient is φ = 1098517824000.

The previous prime is 1221001122109. The next prime is 1221001122167. The reversal of 1221001122121 is 1212211001221.

It is a cyclic number.

It is not a de Polignac number, because 1221001122121 - 2²⁷ = 1220866904393 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1221001122095 and 1221001122104.

It is not an unprimeable number, because it can be changed into a prime (1221001122821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2242105 + ... + 2732953.

It is an arithmetic number, because the mean of its divisors is an integer number (84112056000).

Almost surely, 2^{1221001122121} is an apocalyptic number.

1221001122121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1221001122121 is a deficient number, since it is larger than the sum of its proper divisors (124791773879).

1221001122121 is a wasteful number, since it uses less digits than its factorization.

1221001122121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 493200.

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

Adding to 1221001122121 its reverse (1212211001221), we get a palindrome (2433212123342).

The spelling of 1221001122121 in words is "one trillion, two hundred twenty-one billion, one million, one hundred twenty-two thousand, one hundred twenty-one".