684561 has 8 divisors (see below), whose sum is σ = 918720. Its totient is φ = 453392.

The previous prime is 684559. The next prime is 684569. The reversal of 684561 is 165486.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 684561 - 2¹ = 684559 is a prime.

It is a nialpdrome in base 16.

It is not an unprimeable number, because it can be changed into a prime (684569) 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, 141 + ... + 1178.

It is an arithmetic number, because the mean of its divisors is an integer number (114840).

2⁶⁸⁴⁵⁶¹ is an apocalyptic number.

It is an amenable number.

684561 is a deficient number, since it is larger than the sum of its proper divisors (234159).

684561 is a wasteful number, since it uses less digits than its factorization.

684561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1495.

The product of its digits is 5760, while the sum is 30.

The square root of 684561 is about 827.3820157581. The cubic root of 684561 is about 88.1327627587.

The spelling of 684561 in words is "six hundred eighty-four thousand, five hundred sixty-one".