9121211100121 has 4 divisors (see below), whose sum is σ = 9128513912500. Its totient is φ = 9113908287744.

The previous prime is 9121211100119. The next prime is 9121211100139. The reversal of 9121211100121 is 1210011121219.

It is a happy number.

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 3527394834496 + 5593816265625 = 1878136^2 + 2365125^2 .

It is a cyclic number.

It is not a de Polignac number, because 9121211100121 - 2¹ = 9121211100119 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 9121211100092 and 9121211100101.

It is not an unprimeable number, because it can be changed into a prime (9121211100161) 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, 3651404316 + ... + 3651406813.

It is an arithmetic number, because the mean of its divisors is an integer number (2282128478125).

Almost surely, 2^{9121211100121} is an apocalyptic number.

It is an amenable number.

9121211100121 is a deficient number, since it is larger than the sum of its proper divisors (7302812379).

9121211100121 is a wasteful number, since it uses less digits than its factorization.

9121211100121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7302812378.

The product of its (nonzero) digits is 72, while the sum is 22.

The spelling of 9121211100121 in words is "nine trillion, one hundred twenty-one billion, two hundred eleven million, one hundred thousand, one hundred twenty-one".