728581728 has 96 divisors (see below), whose sum is σ = 2203213824. Its totient is φ = 206502912.

The previous prime is 728581691. The next prime is 728581729. The reversal of 728581728 is 827185827.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (728581729) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 81076 + ... + 89612.

It is an arithmetic number, because the mean of its divisors is an integer number (22950144).

Almost surely, 2^728581728 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 728581728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1101606912).

728581728 is an abundant number, since it is smaller than the sum of its proper divisors (1474632096).

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

728581728 is a wasteful number, since it uses less digits than its factorization.

728581728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8684 (or 8676 counting only the distinct ones).

The product of its digits is 501760, while the sum is 48.

The square root of 728581728 is about 26992.2531108465. The cubic root of 728581728 is about 899.8278386742.

The spelling of 728581728 in words is "seven hundred twenty-eight million, five hundred eighty-one thousand, seven hundred twenty-eight".