720605 has 8 divisors (see below), whose sum is σ = 870912. Its totient is φ = 572368.

The previous prime is 720571. The next prime is 720607. The reversal of 720605 is 506027.

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 720605 - 2¹⁶ = 655069 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 (720607) 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, 404 + ... + 1266.

It is an arithmetic number, because the mean of its divisors is an integer number (108864).

2⁷²⁰⁶⁰⁵ is an apocalyptic number.

It is an amenable number.

720605 is a deficient number, since it is larger than the sum of its proper divisors (150307).

720605 is a wasteful number, since it uses less digits than its factorization.

720605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1035.

The product of its (nonzero) digits is 420, while the sum is 20.

The square root of 720605 is about 848.8845622345. The cubic root of 720605 is about 89.6531920684.

It can be divided in two parts, 720 and 605, that multiplied together give a square (435600 = 660²).

The spelling of 720605 in words is "seven hundred twenty thousand, six hundred five".