17138721157 has 4 divisors (see below), whose sum is σ = 17140311180. Its totient is φ = 17137131136.

The previous prime is 17138721143. The next prime is 17138721161. The reversal of 17138721157 is 75112783171.

17138721157 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 75112783171 = 155201 ⋅483971.

It can be written as a sum of positive squares in 2 ways, for example, as 4879581316 + 12259139841 = 69854^2 + 110721^2 .

It is a cyclic number.

It is not a de Polignac number, because 17138721157 - 2⁷ = 17138721029 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (17138721137) 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 in 3 ways as a sum of consecutive naturals, for example, 778732 + ... + 800437.

It is an arithmetic number, because the mean of its divisors is an integer number (4285077795).

Almost surely, 2^17138721157 is an apocalyptic number.

It is an amenable number.

17138721157 is a deficient number, since it is larger than the sum of its proper divisors (1590023).

17138721157 is a wasteful number, since it uses less digits than its factorization.

17138721157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1590022.

The product of its digits is 82320, while the sum is 43.

The spelling of 17138721157 in words is "seventeen billion, one hundred thirty-eight million, seven hundred twenty-one thousand, one hundred fifty-seven".