1001221121111 has 2 divisors, whose sum is σ = 1001221121112. Its totient is φ = 1001221121110.

The previous prime is 1001221121099. The next prime is 1001221121113. The reversal of 1001221121111 is 1111211221001.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1001221121111 - 2³⁸ = 726343214167 is a prime.

Together with 1001221121113, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1001221121113) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 500610560555 + 500610560556.

It is an arithmetic number, because the mean of its divisors is an integer number (500610560556).

Almost surely, 2^{1001221121111} is an apocalyptic number.

1001221121111 is a deficient number, since it is larger than the sum of its proper divisors (1).

1001221121111 is an equidigital number, since it uses as much as digits as its factorization.

1001221121111 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8, while the sum is 14.

Adding to 1001221121111 its reverse (1111211221001), we get a palindrome (2112432342112).

The spelling of 1001221121111 in words is "one trillion, one billion, two hundred twenty-one million, one hundred twenty-one thousand, one hundred eleven".