684208123 has 4 divisors (see below), whose sum is σ = 700896168. Its totient is φ = 667520080.

The previous prime is 684208079. The next prime is 684208141. The reversal of 684208123 is 321802486.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-684208123 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (684208423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8343961 + ... + 8344042.

It is an arithmetic number, because the mean of its divisors is an integer number (175224042).

Almost surely, 2^684208123 is an apocalyptic number.

684208123 is a deficient number, since it is larger than the sum of its proper divisors (16688045).

684208123 is a wasteful number, since it uses less digits than its factorization.

684208123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16688044.

The product of its (nonzero) digits is 18432, while the sum is 34.

The square root of 684208123 is about 26157.3722495208. The cubic root of 684208123 is about 881.1761661864.

The spelling of 684208123 in words is "six hundred eighty-four million, two hundred eight thousand, one hundred twenty-three".