687857161 has 8 divisors (see below), whose sum is σ = 701333640. Its totient is φ = 674399232.

The previous prime is 687857129. The next prime is 687857201. The reversal of 687857161 is 161758786.

It can be written as a sum of positive squares in 4 ways, for example, as 147015625 + 540841536 = 12125^2 + 23256^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 687857161 - 2⁵ = 687857129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (687857101) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 88105 + ... + 95593.

It is an arithmetic number, because the mean of its divisors is an integer number (87666705).

Almost surely, 2^687857161 is an apocalyptic number.

It is an amenable number.

687857161 is a deficient number, since it is larger than the sum of its proper divisors (13476479).

687857161 is a wasteful number, since it uses less digits than its factorization.

687857161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9275.

The product of its digits is 564480, while the sum is 49.

The square root of 687857161 is about 26227.0311129567. The cubic root of 687857161 is about 882.7398940686.

The spelling of 687857161 in words is "six hundred eighty-seven million, eight hundred fifty-seven thousand, one hundred sixty-one".