720736 has 24 divisors (see below), whose sum is σ = 1439424. Its totient is φ = 355200.

The previous prime is 720703. The next prime is 720743. The reversal of 720736 is 637027.

720736 = 73² + 74² + ... + 136².

It is a self number, because there is not a number n which added to its sum of digits gives 720736.

It is a congruent number.

It is an unprimeable number.

720736 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3121 + ... + 3343.

It is an arithmetic number, because the mean of its divisors is an integer number (59976).

2⁷²⁰⁷³⁶ is an apocalyptic number.

It is an amenable number.

720736 is a deficient number, since it is larger than the sum of its proper divisors (718688).

720736 is a wasteful number, since it uses less digits than its factorization.

720736 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 334 (or 326 counting only the distinct ones).

The product of its (nonzero) digits is 1764, while the sum is 25.

The square root of 720736 is about 848.9617188072. The cubic root of 720736 is about 89.6586244743.

Adding to 720736 its product of nonzero digits (1764), we get a square (722500 = 850²).

The spelling of 720736 in words is "seven hundred twenty thousand, seven hundred thirty-six".