720643 has 16 divisors (see below), whose sum is σ = 921600. Its totient is φ = 558600.

The previous prime is 720619. The next prime is 720653. The reversal of 720643 is 346027.

It is not a de Polignac number, because 720643 - 2⁵ = 720611 is a prime.

It is a Duffinian number.

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

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3678 + ... + 3868.

It is an arithmetic number, because the mean of its divisors is an integer number (57600).

2⁷²⁰⁶⁴³ is an apocalyptic number.

720643 is a deficient number, since it is larger than the sum of its proper divisors (200957).

720643 is a wasteful number, since it uses less digits than its factorization.

720643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 223 (or 209 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 22.

The square root of 720643 is about 848.9069442524. The cubic root of 720643 is about 89.6547679486.

The spelling of 720643 in words is "seven hundred twenty thousand, six hundred forty-three".