30728 has 16 divisors (see below), whose sum is σ = 60480. Its totient is φ = 14608.

The previous prime is 30727. The next prime is 30757. The reversal of 30728 is 82703.

It is not an unprimeable number, because it can be changed into a prime (30727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 101 + ... + 267.

It is an arithmetic number, because the mean of its divisors is an integer number (3780).

2³⁰⁷²⁸ is an apocalyptic number.

It is an amenable number.

30728 is a deficient number, since it is larger than the sum of its proper divisors (29752).

30728 is a wasteful number, since it uses less digits than its factorization.

30728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 196 (or 192 counting only the distinct ones).

The product of its (nonzero) digits is 336, while the sum is 20.

The square root of 30728 is about 175.2940386893. The cubic root of 30728 is about 31.3216595515.

The spelling of 30728 in words is "thirty thousand, seven hundred twenty-eight".