305685128 has 48 divisors (see below), whose sum is σ = 675244800. Its totient is φ = 129336480.

The previous prime is 305685113. The next prime is 305685137. The reversal of 305685128 is 821586503.

305685128 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 305685091 and 305685100.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 26033 + ... + 35903.

It is an arithmetic number, because the mean of its divisors is an integer number (14067600).

Almost surely, 2^305685128 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 305685128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (337622400).

305685128 is an abundant number, since it is smaller than the sum of its proper divisors (369559672).

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

305685128 is a wasteful number, since it uses less digits than its factorization.

305685128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9970 (or 9959 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 38.

The square root of 305685128 is about 17483.8533510208. The cubic root of 305685128 is about 673.6351960459.

The spelling of 305685128 in words is "three hundred five million, six hundred eighty-five thousand, one hundred twenty-eight".