306440 has 32 divisors (see below), whose sum is σ = 708480. Its totient is φ = 119232.

The previous prime is 306437. The next prime is 306457. The reversal of 306440 is 44603.

306440 = 14³ + 15³ + ... + 33³.

306440 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 306440.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1799 + ... + 1961.

It is an arithmetic number, because the mean of its divisors is an integer number (22140).

2³⁰⁶⁴⁴⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 306440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (354240).

306440 is an abundant number, since it is smaller than the sum of its proper divisors (402040).

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

306440 is a wasteful number, since it uses less digits than its factorization.

306440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 221 (or 217 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 17.

The square root of 306440 is about 553.5702304134. The cubic root of 306440 is about 67.4189241475.

The spelling of 306440 in words is "three hundred six thousand, four hundred forty".