1221221101211 has 2 divisors, whose sum is σ = 1221221101212. Its totient is φ = 1221221101210.

The previous prime is 1221221101207. The next prime is 1221221101259. The reversal of 1221221101211 is 1121011221221.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1221221101211 - 2² = 1221221101207 is a prime.

It is a Sophie Germain prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1221221101211.

It is not a weakly prime, because it can be changed into another prime (1221221106211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610610550605 + 610610550606.

It is an arithmetic number, because the mean of its divisors is an integer number (610610550606).

Almost surely, 2^{1221221101211} is an apocalyptic number.

1221221101211 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221221101211 is an equidigital number, since it uses as much as digits as its factorization.

1221221101211 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 1221221101211 its reverse (1121011221221), we get a palindrome (2342232322432).

The spelling of 1221221101211 in words is "one trillion, two hundred twenty-one billion, two hundred twenty-one million, one hundred one thousand, two hundred eleven".