728581 has 6 divisors (see below), whose sum is σ = 847590. Its totient is φ = 624456.

The previous prime is 728579. The next prime is 728627. The reversal of 728581 is 185827.

It can be written as a sum of positive squares in only one way, i.e., 540225 + 188356 = 735^2 + 434^2 .

It is not a de Polignac number, because 728581 - 2¹ = 728579 is a prime.

It is a super-2 number, since 2×728581² = 1061660547122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (728521) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 7386 + ... + 7483.

It is an arithmetic number, because the mean of its divisors is an integer number (141265).

2⁷²⁸⁵⁸¹ is an apocalyptic number.

It is an amenable number.

728581 is a deficient number, since it is larger than the sum of its proper divisors (119009).

728581 is a wasteful number, since it uses less digits than its factorization.

728581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14883 (or 14876 counting only the distinct ones).

The product of its digits is 4480, while the sum is 31.

The square root of 728581 is about 853.5695636561. The cubic root of 728581 is about 89.9827538971.

The spelling of 728581 in words is "seven hundred twenty-eight thousand, five hundred eighty-one".