30728388 has 24 divisors (see below), whose sum is σ = 71809920. Its totient is φ = 10227040.

The previous prime is 30728387. The next prime is 30728417. The reversal of 30728388 is 88382703.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (30728381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8293 + ... + 11411.

It is an arithmetic number, because the mean of its divisors is an integer number (2992080).

Almost surely, 2^30728388 is an apocalyptic number.

It is an amenable number.

30728388 is an abundant number, since it is smaller than the sum of its proper divisors (41081532).

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

30728388 is a wasteful number, since it uses less digits than its factorization.

30728388 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3947 (or 3945 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 39.

The square root of 30728388 is about 5543.3192222711. The cubic root of 30728388 is about 313.2179138295.

The spelling of 30728388 in words is "thirty million, seven hundred twenty-eight thousand, three hundred eighty-eight".