720581 has 4 divisors (see below), whose sum is σ = 722592. Its totient is φ = 718572.

The previous prime is 720571. The next prime is 720607. The reversal of 720581 is 185027.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 720581 - 2¹⁰ = 719557 is a prime.

It is a super-2 number, since 2×720581² = 1038473955122, 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 (720571) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 305 + ... + 1238.

It is an arithmetic number, because the mean of its divisors is an integer number (180648).

2⁷²⁰⁵⁸¹ is an apocalyptic number.

It is an amenable number.

720581 is a deficient number, since it is larger than the sum of its proper divisors (2011).

720581 is a wasteful number, since it uses less digits than its factorization.

720581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2010.

The product of its (nonzero) digits is 560, while the sum is 23.

The square root of 720581 is about 848.8704259191. The cubic root of 720581 is about 89.6521967471.

The spelling of 720581 in words is "seven hundred twenty thousand, five hundred eighty-one".