305813 has 4 divisors (see below), whose sum is σ = 323820. Its totient is φ = 287808.

The previous prime is 305803. The next prime is 305821. The reversal of 305813 is 318503.

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

It can be written as a sum of positive squares in 2 ways, for example, as 237169 + 68644 = 487^2 + 262^2 .

It is a cyclic number.

It is not a de Polignac number, because 305813 - 2⁶ = 305749 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 305813.

It is not an unprimeable number, because it can be changed into a prime (305803) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8978 + ... + 9011.

It is an arithmetic number, because the mean of its divisors is an integer number (80955).

2³⁰⁵⁸¹³ is an apocalyptic number.

It is an amenable number.

305813 is a deficient number, since it is larger than the sum of its proper divisors (18007).

305813 is a wasteful number, since it uses less digits than its factorization.

305813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18006.

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 305813 is about 553.0036166247. The cubic root of 305813 is about 67.3729113025.

The spelling of 305813 in words is "three hundred five thousand, eight hundred thirteen".