30506728 has 32 divisors (see below), whose sum is σ = 67484160. Its totient is φ = 12651840.

The previous prime is 30506701. The next prime is 30506731. The reversal of 30506728 is 82760503.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a self number, because there is not a number n which added to its sum of digits gives 30506728.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7051 + ... + 10522.

It is an arithmetic number, because the mean of its divisors is an integer number (2108880).

Almost surely, 2^30506728 is an apocalyptic number.

It is an amenable number.

30506728 is an abundant number, since it is smaller than the sum of its proper divisors (36977432).

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

30506728 is a wasteful number, since it uses less digits than its factorization.

30506728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17617 (or 17613 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 31.

The square root of 30506728 is about 5523.2895995050. The cubic root of 30506728 is about 312.4629605167.

The spelling of 30506728 in words is "thirty million, five hundred six thousand, seven hundred twenty-eight".