17138721091 has 2 divisors, whose sum is σ = 17138721092. Its totient is φ = 17138721090.

The previous prime is 17138721029. The next prime is 17138721109. The reversal of 17138721091 is 19012783171.

17138721091 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

Together with next prime (17138721109) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 17138721091 - 2⁹ = 17138720579 is a prime.

It is not a weakly prime, because it can be changed into another prime (17138221091) 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, 8569360545 + 8569360546.

It is an arithmetic number, because the mean of its divisors is an integer number (8569360546).

Almost surely, 2^17138721091 is an apocalyptic number.

17138721091 is a deficient number, since it is larger than the sum of its proper divisors (1).

17138721091 is an equidigital number, since it uses as much as digits as its factorization.

17138721091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 21168, while the sum is 40.

The spelling of 17138721091 in words is "seventeen billion, one hundred thirty-eight million, seven hundred twenty-one thousand, ninety-one".