684879 has 16 divisors (see below), whose sum is σ = 1042272. Its totient is φ = 396288.

The previous prime is 684869. The next prime is 684889. The reversal of 684879 is 978486.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (684869) and next prime (684889).

It is not a de Polignac number, because 684879 - 2⁷ = 684751 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 684879.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (684809) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 147 + ... + 1179.

It is an arithmetic number, because the mean of its divisors is an integer number (65142).

2⁶⁸⁴⁸⁷⁹ is an apocalyptic number.

684879 is a deficient number, since it is larger than the sum of its proper divisors (357393).

684879 is a wasteful number, since it uses less digits than its factorization.

684879 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1066.

The product of its digits is 96768, while the sum is 42.

The square root of 684879 is about 827.5741658607. The cubic root of 684879 is about 88.1464074545.

The spelling of 684879 in words is "six hundred eighty-four thousand, eight hundred seventy-nine".