720785 has 12 divisors (see below), whose sum is σ = 937692. Its totient is φ = 531648.

The previous prime is 720779. The next prime is 720791. The reversal of 720785 is 587027.

It is an interprime number because it is at equal distance from previous prime (720779) and next prime (720791).

It can be written as a sum of positive squares in 6 ways, for example, as 322624 + 398161 = 568^2 + 631^2 .

It is a de Polignac number, because none of the positive numbers 2^k-720785 is a prime.

It is a Smith number, since the sum of its digits (29) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 419 + ... + 1271.

It is an arithmetic number, because the mean of its divisors is an integer number (78141).

2⁷²⁰⁷⁸⁵ is an apocalyptic number.

It is an amenable number.

720785 is a deficient number, since it is larger than the sum of its proper divisors (216907).

720785 is a wasteful number, since it uses less digits than its factorization.

720785 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 884 (or 871 counting only the distinct ones).

The product of its (nonzero) digits is 3920, while the sum is 29.

The square root of 720785 is about 848.9905770973. The cubic root of 720785 is about 89.6606562738.

The spelling of 720785 in words is "seven hundred twenty thousand, seven hundred eighty-five".