728745 has 16 divisors (see below), whose sum is σ = 1227840. Its totient is φ = 368064.

The previous prime is 728743. The next prime is 728747. The reversal of 728745 is 547827.

728745 = T₁₅₇ + T₁₅₈ + ... + T₂₀₁.

It is an interprime number because it is at equal distance from previous prime (728743) and next prime (728747).

It is not a de Polignac number, because 728745 - 2¹ = 728743 is a prime.

728745 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (728743) 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 15 ways as a sum of consecutive naturals, for example, 994 + ... + 1563.

It is an arithmetic number, because the mean of its divisors is an integer number (76740).

2⁷²⁸⁷⁴⁵ is an apocalyptic number.

It is an amenable number.

728745 is a deficient number, since it is larger than the sum of its proper divisors (499095).

728745 is a wasteful number, since it uses less digits than its factorization.

728745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2584.

The product of its digits is 15680, while the sum is 33.

The square root of 728745 is about 853.6656254061. The cubic root of 728745 is about 89.9895049490.

The spelling of 728745 in words is "seven hundred twenty-eight thousand, seven hundred forty-five".