1221042443393 has 2 divisors, whose sum is σ = 1221042443394. Its totient is φ = 1221042443392.

The previous prime is 1221042443339. The next prime is 1221042443461. The reversal of 1221042443393 is 3933442401221.

Together with previous prime (1221042443339) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1009237233664 + 211805209729 = 1004608^2 + 460223^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221042443393 - 2⁴⁰ = 121530815617 is a prime.

It is not a weakly prime, because it can be changed into another prime (1221042443993) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610521221696 + 610521221697.

It is an arithmetic number, because the mean of its divisors is an integer number (610521221697).

Almost surely, 2^{1221042443393} is an apocalyptic number.

It is an amenable number.

1221042443393 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221042443393 is an equidigital number, since it uses as much as digits as its factorization.

1221042443393 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 124416, while the sum is 38.

The spelling of 1221042443393 in words is "one trillion, two hundred twenty-one billion, forty-two million, four hundred forty-three thousand, three hundred ninety-three".