687043165 has 4 divisors (see below), whose sum is σ = 824451804. Its totient is φ = 549634528.

The previous prime is 687043163. The next prime is 687043169. The reversal of 687043165 is 561340786.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 123787876 + 563255289 = 11126^2 + 23733^2 .

It is a cyclic number.

It is not a de Polignac number, because 687043165 - 2¹ = 687043163 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (687043163) 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, 68704312 + ... + 68704321.

It is an arithmetic number, because the mean of its divisors is an integer number (206112951).

Almost surely, 2^687043165 is an apocalyptic number.

It is an amenable number.

687043165 is a deficient number, since it is larger than the sum of its proper divisors (137408639).

687043165 is a wasteful number, since it uses less digits than its factorization.

687043165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 137408638.

The product of its (nonzero) digits is 120960, while the sum is 40.

The square root of 687043165 is about 26211.5082549631. The cubic root of 687043165 is about 882.3915512207.

The spelling of 687043165 in words is "six hundred eighty-seven million, forty-three thousand, one hundred sixty-five".