171688513 has 2 divisors, whose sum is σ = 171688514. Its totient is φ = 171688512.

The previous prime is 171688511. The next prime is 171688523. The reversal of 171688513 is 315886171.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 161493264 + 10195249 = 12708^2 + 3193^2 .

It is a cyclic number.

It is not a de Polignac number, because 171688513 - 2¹ = 171688511 is a prime.

Together with 171688511, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (171688511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 85844256 + 85844257.

It is an arithmetic number, because the mean of its divisors is an integer number (85844257).

Almost surely, 2^171688513 is an apocalyptic number.

It is an amenable number.

171688513 is a deficient number, since it is larger than the sum of its proper divisors (1).

171688513 is an equidigital number, since it uses as much as digits as its factorization.

171688513 is an evil number, because the sum of its binary digits is even.

The product of its digits is 40320, while the sum is 40.

The square root of 171688513 is about 13102.9963367163. The cubic root of 171688513 is about 555.7938621737.

The spelling of 171688513 in words is "one hundred seventy-one million, six hundred eighty-eight thousand, five hundred thirteen".