213687 has 6 divisors (see below), whose sum is σ = 308672. Its totient is φ = 142452.

The previous prime is 213659. The next prime is 213713. The reversal of 213687 is 786312.

It is not a de Polignac number, because 213687 - 2⁶ = 213623 is a prime.

It is a Duffinian number.

213687 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 213687.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213637) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 11863 + ... + 11880.

2²¹³⁶⁸⁷ is an apocalyptic number.

213687 is a deficient number, since it is larger than the sum of its proper divisors (94985).

213687 is a wasteful number, since it uses less digits than its factorization.

213687 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23749 (or 23746 counting only the distinct ones).

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

The square root of 213687 is about 462.2629122047. The cubic root of 213687 is about 59.7850642968.

Adding to 213687 its reverse (786312), we get a palindrome (999999).

It can be divided in two parts, 213 and 687, that added together give a square (900 = 30²).

The spelling of 213687 in words is "two hundred thirteen thousand, six hundred eighty-seven".