305820 has 36 divisors (see below), whose sum is σ = 928200. Its totient is φ = 81504.

The previous prime is 305803. The next prime is 305821. The reversal of 305820 is 28503.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an Ulam number.

It is a junction number, because it is equal to n+sod(n) for n = 305793 and 305802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (305821) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 670 + ... + 1029.

2³⁰⁵⁸²⁰ is an apocalyptic number.

305820 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

305820 is an abundant number, since it is smaller than the sum of its proper divisors (622380).

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

305820 is a wasteful number, since it uses less digits than its factorization.

305820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1714 (or 1709 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 305820 is about 553.0099456610. The cubic root of 305820 is about 67.3734253495.

The spelling of 305820 in words is "three hundred five thousand, eight hundred twenty".