721440589 has 8 divisors (see below), whose sum is σ = 728628120. Its totient is φ = 714263616.

The previous prime is 721440571. The next prime is 721440593. The reversal of 721440589 is 985044127.

It can be written as a sum of positive squares in 4 ways, for example, as 9351364 + 712089225 = 3058^2 + 26685^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 721440589 - 2⁵ = 721440557 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721440529) 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 7 ways as a sum of consecutive naturals, for example, 252879 + ... + 255715.

It is an arithmetic number, because the mean of its divisors is an integer number (91078515).

Almost surely, 2^721440589 is an apocalyptic number.

It is an amenable number.

721440589 is a deficient number, since it is larger than the sum of its proper divisors (7187531).

721440589 is a wasteful number, since it uses less digits than its factorization.

721440589 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5279.

The product of its (nonzero) digits is 80640, while the sum is 40.

The square root of 721440589 is about 26859.6461071251. The cubic root of 721440589 is about 896.8783161164.

The spelling of 721440589 in words is "seven hundred twenty-one million, four hundred forty thousand, five hundred eighty-nine".