1221201121099 has 2 divisors, whose sum is σ = 1221201121100. Its totient is φ = 1221201121098.

The previous prime is 1221201121097. The next prime is 1221201121187. The reversal of 1221201121099 is 9901211021221.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1221201121099 - 2¹ = 1221201121097 is a prime.

Together with 1221201121097, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 1221201121099.

It is not a weakly prime, because it can be changed into another prime (1221201121097) 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 as a sum of consecutive naturals, namely, 610600560549 + 610600560550.

It is an arithmetic number, because the mean of its divisors is an integer number (610600560550).

Almost surely, 2^{1221201121099} is an apocalyptic number.

1221201121099 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221201121099 is an equidigital number, since it uses as much as digits as its factorization.

1221201121099 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1296, while the sum is 31.

The spelling of 1221201121099 in words is "one trillion, two hundred twenty-one billion, two hundred one million, one hundred twenty-one thousand, ninety-nine".