687811171 has 2 divisors, whose sum is σ = 687811172. Its totient is φ = 687811170.

The previous prime is 687811141. The next prime is 687811199. The reversal of 687811171 is 171118786.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 687811171 - 2⁵ = 687811139 is a prime.

It is not a weakly prime, because it can be changed into another prime (687811141) 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, 343905585 + 343905586.

It is an arithmetic number, because the mean of its divisors is an integer number (343905586).

Almost surely, 2^687811171 is an apocalyptic number.

687811171 is a deficient number, since it is larger than the sum of its proper divisors (1).

687811171 is an equidigital number, since it uses as much as digits as its factorization.

687811171 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18816, while the sum is 40.

The square root of 687811171 is about 26226.1543311253. The cubic root of 687811171 is about 882.7202203558.

The spelling of 687811171 in words is "six hundred eighty-seven million, eight hundred eleven thousand, one hundred seventy-one".