305640 has 64 divisors (see below), whose sum is σ = 1022400. Its totient is φ = 81216.

The previous prime is 305639. The next prime is 305663. The reversal of 305640 is 46503.

It is a happy number.

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

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 939 + ... + 1221.

It is an arithmetic number, because the mean of its divisors is an integer number (15975).

2³⁰⁵⁶⁴⁰ is an apocalyptic number.

305640 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 305640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (511200).

305640 is an abundant number, since it is smaller than the sum of its proper divisors (716760).

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

305640 is a wasteful number, since it uses less digits than its factorization.

305640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 303 (or 293 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 18.

The square root of 305640 is about 552.8471759899. The cubic root of 305640 is about 67.3602045044.

The spelling of 305640 in words is "three hundred five thousand, six hundred forty".