687415 has 4 divisors (see below), whose sum is σ = 824904. Its totient is φ = 549928.

The previous prime is 687413. The next prime is 687431. The reversal of 687415 is 514786.

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

It is a cyclic number.

It is not a de Polignac number, because 687415 - 2¹ = 687413 is a prime.

It is a Smith number, since the sum of its digits (31) 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 (687413) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 68737 + ... + 68746.

It is an arithmetic number, because the mean of its divisors is an integer number (206226).

2⁶⁸⁷⁴¹⁵ is an apocalyptic number.

687415 is a deficient number, since it is larger than the sum of its proper divisors (137489).

687415 is a wasteful number, since it uses less digits than its factorization.

687415 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 137488.

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

The square root of 687415 is about 829.1049390759. The cubic root of 687415 is about 88.2550709047.

It can be divided in two parts, 6874 and 15, that added together give a square (6889 = 83²).

The spelling of 687415 in words is "six hundred eighty-seven thousand, four hundred fifteen".