684891 has 6 divisors (see below), whose sum is σ = 989300. Its totient is φ = 456588.

The previous prime is 684889. The next prime is 684923. The reversal of 684891 is 198486.

It is a happy number.

It is not a de Polignac number, because 684891 - 2¹ = 684889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (684841) 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, 38041 + ... + 38058.

2⁶⁸⁴⁸⁹¹ is an apocalyptic number.

684891 is a deficient number, since it is larger than the sum of its proper divisors (304409).

684891 is a wasteful number, since it uses less digits than its factorization.

684891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76105 (or 76102 counting only the distinct ones).

The product of its digits is 13824, while the sum is 36.

The square root of 684891 is about 827.5814159344. The cubic root of 684891 is about 88.1469222660.

The spelling of 684891 in words is "six hundred eighty-four thousand, eight hundred ninety-one".