17139785561 has 2 divisors, whose sum is σ = 17139785562. Its totient is φ = 17139785560.

The previous prime is 17139785557. The next prime is 17139785567. The reversal of 17139785561 is 16558793171.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16066830025 + 1072955536 = 126755^2 + 32756^2 .

It is an emirp because it is prime and its reverse (16558793171) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 17139785561 - 2² = 17139785557 is a prime.

It is not a weakly prime, because it can be changed into another prime (17139785567) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8569892780 + 8569892781.

It is an arithmetic number, because the mean of its divisors is an integer number (8569892781).

Almost surely, 2^17139785561 is an apocalyptic number.

It is an amenable number.

17139785561 is a deficient number, since it is larger than the sum of its proper divisors (1).

17139785561 is an equidigital number, since it uses as much as digits as its factorization.

17139785561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1587600, while the sum is 53.

The spelling of 17139785561 in words is "seventeen billion, one hundred thirty-nine million, seven hundred eighty-five thousand, five hundred sixty-one".