1221221101109 has 2 divisors, whose sum is σ = 1221221101110. Its totient is φ = 1221221101108.

The previous prime is 1221221101043. The next prime is 1221221101127. The reversal of 1221221101109 is 9011011221221.

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., 1155672300484 + 65548800625 = 1075022^2 + 256025^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1221221101109 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221221101189) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610610550554 + 610610550555.

It is an arithmetic number, because the mean of its divisors is an integer number (610610550555).

Almost surely, 2^{1221221101109} is an apocalyptic number.

It is an amenable number.

1221221101109 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221221101109 is an equidigital number, since it uses as much as digits as its factorization.

1221221101109 is an odious number, because the sum of its binary digits is odd.

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

The spelling of 1221221101109 in words is "one trillion, two hundred twenty-one billion, two hundred twenty-one million, one hundred one thousand, one hundred nine".