720189 has 6 divisors (see below), whose sum is σ = 1040286. Its totient is φ = 480120.

The previous prime is 720179. The next prime is 720193. The reversal of 720189 is 981027.

It can be written as a sum of positive squares in only one way, i.e., 412164 + 308025 = 642^2 + 555^2 .

It is not a de Polignac number, because 720189 - 2⁴ = 720173 is a prime.

It is a super-3 number, since 3×720189³ = 1120626029892333807, which contains 333 as substring.

It is a Curzon number.

720189 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (720179) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 40002 + ... + 40019.

It is an arithmetic number, because the mean of its divisors is an integer number (173381).

2⁷²⁰¹⁸⁹ is an apocalyptic number.

It is an amenable number.

720189 is a deficient number, since it is larger than the sum of its proper divisors (320097).

720189 is a wasteful number, since it uses less digits than its factorization.

720189 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80027 (or 80024 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 27.

The square root of 720189 is about 848.6394994342. The cubic root of 720189 is about 89.6359367033.

It can be divided in two parts, 72018 and 9, that added together give a palindrome (72027).

The spelling of 720189 in words is "seven hundred twenty thousand, one hundred eighty-nine".