1221289356863 has 2 divisors, whose sum is σ = 1221289356864. Its totient is φ = 1221289356862.

The previous prime is 1221289356853. The next prime is 1221289356901. The reversal of 1221289356863 is 3686539821221.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1221289356863 - 2⁸ = 1221289356607 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1221289356799 and 1221289356808.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221289356853) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610644678431 + 610644678432.

It is an arithmetic number, because the mean of its divisors is an integer number (610644678432).

Almost surely, 2^{1221289356863} is an apocalyptic number.

1221289356863 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221289356863 is an equidigital number, since it uses as much as digits as its factorization.

1221289356863 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7464960, while the sum is 56.

The spelling of 1221289356863 in words is "one trillion, two hundred twenty-one billion, two hundred eighty-nine million, three hundred fifty-six thousand, eight hundred sixty-three".