721085 has 8 divisors (see below), whose sum is σ = 895320. Its totient is φ = 556864.

The previous prime is 721079. The next prime is 721087. The reversal of 721085 is 580127.

It can be written as a sum of positive squares in 4 ways, for example, as 114244 + 606841 = 338^2 + 779^2 .

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 721085 - 2⁸ = 720829 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 721085.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721087) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2342 + ... + 2631.

It is an arithmetic number, because the mean of its divisors is an integer number (111915).

2⁷²¹⁰⁸⁵ is an apocalyptic number.

It is an amenable number.

721085 is a deficient number, since it is larger than the sum of its proper divisors (174235).

721085 is a wasteful number, since it uses less digits than its factorization.

721085 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5007.

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

The square root of 721085 is about 849.1672391231. The cubic root of 721085 is about 89.6730938550.

The spelling of 721085 in words is "seven hundred twenty-one thousand, eighty-five".