30728736 has 72 divisors (see below), whose sum is σ = 91203840. Its totient is φ = 9795456.

The previous prime is 30728723. The next prime is 30728749. The reversal of 30728736 is 63782703.

It is an interprime number because it is at equal distance from previous prime (30728723) and next prime (30728749).

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 30728736.

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, 4305 + ... + 8943.

It is an arithmetic number, because the mean of its divisors is an integer number (1266720).

Almost surely, 2^30728736 is an apocalyptic number.

30728736 is a gapful number since it is divisible by the number (36) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 30728736, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45601920).

30728736 is an abundant number, since it is smaller than the sum of its proper divisors (60475104).

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

30728736 is a wasteful number, since it uses less digits than its factorization.

30728736 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4678 (or 4667 counting only the distinct ones).

The product of its (nonzero) digits is 42336, while the sum is 36.

The square root of 30728736 is about 5543.3506113180. The cubic root of 30728736 is about 313.2190962261.

The spelling of 30728736 in words is "thirty million, seven hundred twenty-eight thousand, seven hundred thirty-six".