30813728 has 24 divisors (see below), whose sum is σ = 66180240. Its totient is φ = 14006080.

The previous prime is 30813719. The next prime is 30813733. The reversal of 30813728 is 82731803.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a junction number, because it is equal to n+sod(n) for n = 30813694 and 30813703.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 43418 + ... + 44121.

It is an arithmetic number, because the mean of its divisors is an integer number (2757510).

Almost surely, 2^30813728 is an apocalyptic number.

It is an amenable number.

30813728 is an abundant number, since it is smaller than the sum of its proper divisors (35366512).

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

30813728 is a wasteful number, since it uses less digits than its factorization.

30813728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87560 (or 87552 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 30813728 is about 5551.0114393685. The cubic root of 30813728 is about 313.5076058854.

It can be divided in two parts, 308 and 13728, that multiplied together give a palindrome (4228224).

The spelling of 30813728 in words is "thirty million, eight hundred thirteen thousand, seven hundred twenty-eight".