1221555323333 has 2 divisors, whose sum is σ = 1221555323334. Its totient is φ = 1221555323332.

The previous prime is 1221555323327. The next prime is 1221555323371. The reversal of 1221555323333 is 3333235551221.

It is an a-pointer prime, because the next prime (1221555323371) can be obtained adding 1221555323333 to its sum of digits (38).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1060864980289 + 160690343044 = 1029983^2 + 400862^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221555323333 - 2²⁰ = 1221554274757 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221555323323) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610777661666 + 610777661667.

It is an arithmetic number, because the mean of its divisors is an integer number (610777661667).

Almost surely, 2^{1221555323333} is an apocalyptic number.

It is an amenable number.

1221555323333 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221555323333 is an equidigital number, since it uses as much as digits as its factorization.

1221555323333 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 243000, while the sum is 38.

The spelling of 1221555323333 in words is "one trillion, two hundred twenty-one billion, five hundred fifty-five million, three hundred twenty-three thousand, three hundred thirty-three".