1205310728669 has 2 divisors, whose sum is σ = 1205310728670. Its totient is φ = 1205310728668.

The previous prime is 1205310728663. The next prime is 1205310728689. The reversal of 1205310728669 is 9668270135021.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1069234585444 + 136076143225 = 1034038^2 + 368885^2 .

It is a cyclic number.

It is not a de Polignac number, because 1205310728669 - 2²⁰ = 1205309680093 is a prime.

It is a super-2 number, since 2×1205310728669² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1205310728663) 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, 602655364334 + 602655364335.

It is an arithmetic number, because the mean of its divisors is an integer number (602655364335).

Almost surely, 2^{1205310728669} is an apocalyptic number.

It is an amenable number.

1205310728669 is a deficient number, since it is larger than the sum of its proper divisors (1).

1205310728669 is an equidigital number, since it uses as much as digits as its factorization.

1205310728669 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1088640, while the sum is 50.

The spelling of 1205310728669 in words is "one trillion, two hundred five billion, three hundred ten million, seven hundred twenty-eight thousand, six hundred sixty-nine".