684071 has 4 divisors (see below), whose sum is σ = 697032. Its totient is φ = 671112.

The previous prime is 684053. The next prime is 684091. The reversal of 684071 is 170486.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 170486 = 2 ⋅85243.

It is a cyclic number.

It is not a de Polignac number, because 684071 - 2⁶ = 684007 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 684071.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (684091) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6401 + ... + 6506.

It is an arithmetic number, because the mean of its divisors is an integer number (174258).

2⁶⁸⁴⁰⁷¹ is an apocalyptic number.

684071 is a deficient number, since it is larger than the sum of its proper divisors (12961).

684071 is a wasteful number, since it uses less digits than its factorization.

684071 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12960.

The product of its (nonzero) digits is 1344, while the sum is 26.

The square root of 684071 is about 827.0858480230. The cubic root of 684071 is about 88.1117296383. Note that the first 3 decimals are identical.

The spelling of 684071 in words is "six hundred eighty-four thousand, seventy-one".