720656 has 20 divisors (see below), whose sum is σ = 1417692. Its totient is φ = 354816.

The previous prime is 720653. The next prime is 720661. The reversal of 720656 is 656027.

It can be written as a sum of positive squares in 2 ways, for example, as 173056 + 547600 = 416^2 + 740^2 .

It is a hoax number, since the sum of its digits (26) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (720653) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 860 + ... + 1476.

2⁷²⁰⁶⁵⁶ is an apocalyptic number.

It is an amenable number.

720656 is a deficient number, since it is larger than the sum of its proper divisors (697036).

720656 is a wasteful number, since it uses less digits than its factorization.

720656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 698 (or 692 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 26.

The square root of 720656 is about 848.9146011231. The cubic root of 720656 is about 89.6553070528.

The spelling of 720656 in words is "seven hundred twenty thousand, six hundred fifty-six".