684642 has 16 divisors (see below), whose sum is σ = 1564992. Its totient is φ = 195600.

The previous prime is 684637. The next prime is 684643. The reversal of 684642 is 246486.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 684642.

It is not an unprimeable number, because it can be changed into a prime (684643) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8109 + ... + 8192.

It is an arithmetic number, because the mean of its divisors is an integer number (97812).

2⁶⁸⁴⁶⁴² is an apocalyptic number.

684642 is an abundant number, since it is smaller than the sum of its proper divisors (880350).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

684642 is a wasteful number, since it uses less digits than its factorization.

684642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16313.

The product of its digits is 9216, while the sum is 30.

The square root of 684642 is about 827.4309638876. The cubic root of 684642 is about 88.1362386954.

It can be divided in two parts, 684 and 642, that added together give a triangular number (1326 = T₅₁).

The spelling of 684642 in words is "six hundred eighty-four thousand, six hundred forty-two".