720540 has 36 divisors (see below), whose sum is σ = 2186184. Its totient is φ = 192096.

The previous prime is 720527. The next prime is 720547. The reversal of 720540 is 45027.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

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

720540 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1822 + ... + 2181.

2⁷²⁰⁵⁴⁰ is an apocalyptic number.

It is an amenable number.

720540 is an abundant number, since it is smaller than the sum of its proper divisors (1465644).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

720540 is a wasteful number, since it uses less digits than its factorization.

720540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4018 (or 4013 counting only the distinct ones).

The product of its (nonzero) digits is 280, while the sum is 18.

The square root of 720540 is about 848.8462758356. The cubic root of 720540 is about 89.6504963555.

Adding to 720540 its reverse (45027), we get a palindrome (765567).

The spelling of 720540 in words is "seven hundred twenty thousand, five hundred forty".