687123 has 20 divisors (see below), whose sum is σ = 1089000. Its totient is φ = 430272.

The previous prime is 687121. The next prime is 687131. The reversal of 687123 is 321786.

687123 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 687123 - 2¹ = 687121 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (687121) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1128 + ... + 1626.

It is an arithmetic number, because the mean of its divisors is an integer number (54450).

2⁶⁸⁷¹²³ is an apocalyptic number.

687123 is a deficient number, since it is larger than the sum of its proper divisors (401877).

687123 is a wasteful number, since it uses less digits than its factorization.

687123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 528 (or 519 counting only the distinct ones).

The product of its digits is 2016, while the sum is 27.

The square root of 687123 is about 828.9288268603. The cubic root of 687123 is about 88.2425728113.

The spelling of 687123 in words is "six hundred eighty-seven thousand, one hundred twenty-three".