1272839905321 has 2 divisors, whose sum is σ = 1272839905322. Its totient is φ = 1272839905320.

The previous prime is 1272839905307. The next prime is 1272839905331. The reversal of 1272839905321 is 1235099382721.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1139746272921 + 133093632400 = 1067589^2 + 364820^2 .

It is a cyclic number.

It is not a de Polignac number, because 1272839905321 - 2¹¹ = 1272839903273 is a prime.

It is a super-2 number, since 2×1272839905321² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1272839905331) 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, 636419952660 + 636419952661.

It is an arithmetic number, because the mean of its divisors is an integer number (636419952661).

Almost surely, 2^{1272839905321} is an apocalyptic number.

It is an amenable number.

1272839905321 is a deficient number, since it is larger than the sum of its proper divisors (1).

1272839905321 is an equidigital number, since it uses as much as digits as its factorization.

1272839905321 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1632960, while the sum is 52.

The spelling of 1272839905321 in words is "one trillion, two hundred seventy-two billion, eight hundred thirty-nine million, nine hundred five thousand, three hundred twenty-one".