305686 has 4 divisors (see below), whose sum is σ = 458532. Its totient is φ = 152842.

The previous prime is 305663. The next prime is 305717. The reversal of 305686 is 686503.

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

It is a congruent number.

It is an unprimeable number.

305686 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 76420 + ... + 76423.

It is an arithmetic number, because the mean of its divisors is an integer number (114633).

2³⁰⁵⁶⁸⁶ is an apocalyptic number.

305686 is a deficient number, since it is larger than the sum of its proper divisors (152846).

305686 is a wasteful number, since it uses less digits than its factorization.

305686 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 152845.

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 305686 is about 552.8887772419. Note that the first 3 decimals coincide. The cubic root of 305686 is about 67.3635836584.

The spelling of 305686 in words is "three hundred five thousand, six hundred eighty-six".