1221221201111 has 2 divisors, whose sum is σ = 1221221201112. Its totient is φ = 1221221201110.

The previous prime is 1221221201047. The next prime is 1221221201147. The reversal of 1221221201111 is 1111021221221.

It is a strong prime.

It is an emirp because it is prime and its reverse (1111021221221) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1221221201111 - 2⁶ = 1221221201047 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1221221201111.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221221201191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610610600555 + 610610600556.

It is an arithmetic number, because the mean of its divisors is an integer number (610610600556).

Almost surely, 2^{1221221201111} is an apocalyptic number.

1221221201111 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221221201111 is an equidigital number, since it uses as much as digits as its factorization.

1221221201111 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 1221221201111 its reverse (1111021221221), we get a palindrome (2332242422332).

The spelling of 1221221201111 in words is "one trillion, two hundred twenty-one billion, two hundred twenty-one million, two hundred one thousand, one hundred eleven".