1221100111229 has 2 divisors, whose sum is σ = 1221100111230. Its totient is φ = 1221100111228.

The previous prime is 1221100111123. The next prime is 1221100111237. The reversal of 1221100111229 is 9221110011221.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 962553285604 + 258546825625 = 981098^2 + 508475^2 .

It is an emirp because it is prime and its reverse (9221110011221) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1221100111229 - 2¹² = 1221100107133 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221100111279) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610550055614 + 610550055615.

It is an arithmetic number, because the mean of its divisors is an integer number (610550055615).

Almost surely, 2^{1221100111229} is an apocalyptic number.

It is an amenable number.

1221100111229 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221100111229 is an equidigital number, since it uses as much as digits as its factorization.

1221100111229 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 144, while the sum is 23.

The spelling of 1221100111229 in words is "one trillion, two hundred twenty-one billion, one hundred million, one hundred eleven thousand, two hundred twenty-nine".