1221003121111 has 2 divisors, whose sum is σ = 1221003121112. Its totient is φ = 1221003121110.

The previous prime is 1221003121033. The next prime is 1221003121123. The reversal of 1221003121111 is 1111213001221.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1221003121111 - 2⁹ = 1221003120599 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221003121181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610501560555 + 610501560556.

It is an arithmetic number, because the mean of its divisors is an integer number (610501560556).

Almost surely, 2^{1221003121111} is an apocalyptic number.

1221003121111 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221003121111 is an equidigital number, since it uses as much as digits as its factorization.

1221003121111 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24, while the sum is 16.

Adding to 1221003121111 its reverse (1111213001221), we get a palindrome (2332216122332).

The spelling of 1221003121111 in words is "one trillion, two hundred twenty-one billion, three million, one hundred twenty-one thousand, one hundred eleven".