1221055311101 has 2 divisors, whose sum is σ = 1221055311102. Its totient is φ = 1221055311100.

The previous prime is 1221055311083. The next prime is 1221055311121. The reversal of 1221055311101 is 1011135501221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1220649328900 + 405982201 = 1104830^2 + 20149^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1221055311101 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221055311121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610527655550 + 610527655551.

It is an arithmetic number, because the mean of its divisors is an integer number (610527655551).

Almost surely, 2^{1221055311101} is an apocalyptic number.

It is an amenable number.

1221055311101 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221055311101 is an equidigital number, since it uses as much as digits as its factorization.

1221055311101 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 300, while the sum is 23.

The spelling of 1221055311101 in words is "one trillion, two hundred twenty-one billion, fifty-five million, three hundred eleven thousand, one hundred one".