723581 has 4 divisors (see below), whose sum is σ = 727452. Its totient is φ = 719712.

The previous prime is 723563. The next prime is 723587. The reversal of 723581 is 185327.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 403225 + 320356 = 635^2 + 566^2 .

It is a cyclic number.

It is not a de Polignac number, because 723581 - 2¹⁴ = 707197 is a prime.

It is a super-2 number, since 2×723581² = 1047138927122, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 723581.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (723587) 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 3 ways as a sum of consecutive naturals, for example, 1640 + ... + 2033.

It is an arithmetic number, because the mean of its divisors is an integer number (181863).

2⁷²³⁵⁸¹ is an apocalyptic number.

It is an amenable number.

723581 is a deficient number, since it is larger than the sum of its proper divisors (3871).

723581 is a wasteful number, since it uses less digits than its factorization.

723581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3870.

The product of its digits is 1680, while the sum is 26.

The square root of 723581 is about 850.6356446799. The cubic root of 723581 is about 89.7764410266.

The spelling of 723581 in words is "seven hundred twenty-three thousand, five hundred eighty-one".