1221201221011 has 2 divisors, whose sum is σ = 1221201221012. Its totient is φ = 1221201221010.

The previous prime is 1221201220979. The next prime is 1221201221027. The reversal of 1221201221011 is 1101221021221.

It is an a-pointer prime, because the next prime (1221201221027) can be obtained adding 1221201221011 to its sum of digits (16).

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1221201221011 - 2⁵ = 1221201220979 is a prime.

It is not a weakly prime, because it can be changed into another prime (1221201221081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610600610505 + 610600610506.

It is an arithmetic number, because the mean of its divisors is an integer number (610600610506).

Almost surely, 2^{1221201221011} is an apocalyptic number.

1221201221011 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221201221011 is an equidigital number, since it uses as much as digits as its factorization.

1221201221011 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 16.

Adding to 1221201221011 its reverse (1101221021221), we get a palindrome (2322422242232).

The spelling of 1221201221011 in words is "one trillion, two hundred twenty-one billion, two hundred one million, two hundred twenty-one thousand, eleven".