720545 has 24 divisors (see below), whose sum is σ = 1071144. Its totient is φ = 462336.

The previous prime is 720527. The next prime is 720547. The reversal of 720545 is 545027.

It can be written as a sum of positive squares in 4 ways, for example, as 305809 + 414736 = 553^2 + 644^2 .

It is not a de Polignac number, because 720545 - 2⁶ = 720481 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 720545.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (720547) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4079 + ... + 4251.

It is an arithmetic number, because the mean of its divisors is an integer number (44631).

2⁷²⁰⁵⁴⁵ is an apocalyptic number.

It is an amenable number.

720545 is a deficient number, since it is larger than the sum of its proper divisors (350599).

720545 is a wasteful number, since it uses less digits than its factorization.

720545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 209 (or 202 counting only the distinct ones).

The product of its (nonzero) digits is 1400, while the sum is 23.

The square root of 720545 is about 848.8492210045. The cubic root of 720545 is about 89.6507037237.

The spelling of 720545 in words is "seven hundred twenty thousand, five hundred forty-five".