1221000020263 has 2 divisors, whose sum is σ = 1221000020264. Its totient is φ = 1221000020262.

The previous prime is 1221000020209. The next prime is 1221000020267. The reversal of 1221000020263 is 3620200001221.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1221000020263 - 2¹⁷ = 1220999889191 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1221000020263.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221000020267) 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, 610500010131 + 610500010132.

It is an arithmetic number, because the mean of its divisors is an integer number (610500010132).

Almost surely, 2^{1221000020263} is an apocalyptic number.

1221000020263 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221000020263 is an equidigital number, since it uses as much as digits as its factorization.

1221000020263 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 1221000020263 its reverse (3620200001221), we get a palindrome (4841200021484).

The spelling of 1221000020263 in words is "one trillion, two hundred twenty-one billion, twenty thousand, two hundred sixty-three".