684729 has 6 divisors (see below), whose sum is σ = 989066. Its totient is φ = 456480.

The previous prime is 684727. The next prime is 684731. The reversal of 684729 is 927486.

It is an interprime number because it is at equal distance from previous prime (684727) and next prime (684731).

It can be written as a sum of positive squares in only one way, i.e., 393129 + 291600 = 627^2 + 540^2 .

It is not a de Polignac number, because 684729 - 2¹ = 684727 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 684693 and 684702.

It is not an unprimeable number, because it can be changed into a prime (684727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 38032 + ... + 38049.

2⁶⁸⁴⁷²⁹ is an apocalyptic number.

It is an amenable number.

684729 is a deficient number, since it is larger than the sum of its proper divisors (304337).

684729 is a wasteful number, since it uses less digits than its factorization.

684729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76087 (or 76084 counting only the distinct ones).

The product of its digits is 24192, while the sum is 36.

The square root of 684729 is about 827.4835345794. The cubic root of 684729 is about 88.1399718036.

The spelling of 684729 in words is "six hundred eighty-four thousand, seven hundred twenty-nine".