687145 has 8 divisors (see below), whose sum is σ = 840456. Its totient is φ = 539136.

The previous prime is 687139. The next prime is 687151. The reversal of 687145 is 541786.

687145 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (687139) and next prime (687151).

It can be written as a sum of positive squares in 4 ways, for example, as 151321 + 535824 = 389^2 + 732^2 .

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 687145 - 2⁷ = 687017 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1032 + ... + 1561.

It is an arithmetic number, because the mean of its divisors is an integer number (105057).

2⁶⁸⁷¹⁴⁵ is an apocalyptic number.

It is an amenable number.

687145 is a deficient number, since it is larger than the sum of its proper divisors (153311).

687145 is a wasteful number, since it uses less digits than its factorization.

687145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2651.

The product of its digits is 6720, while the sum is 31.

The square root of 687145 is about 828.9420968922. The cubic root of 687145 is about 88.2435145718.

The spelling of 687145 in words is "six hundred eighty-seven thousand, one hundred forty-five".