720740 has 12 divisors (see below), whose sum is σ = 1513596. Its totient is φ = 288288.

The previous prime is 720703. The next prime is 720743. The reversal of 720740 is 47027.

It can be written as a sum of positive squares in 2 ways, for example, as 155236 + 565504 = 394^2 + 752^2 .

It is a super-2 number, since 2×720740² = 1038932295200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20), and also a Moran number because the ratio is a prime number: 36037 = 720740 / (7 + 2 + 0 + 7 + 4 + 0).

720740 is a modest number, since divided by 740 gives 720 as remainder.

It is not an unprimeable number, because it can be changed into a prime (720743) by changing a digit.

720740 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 3 ways as a sum of consecutive naturals, for example, 17999 + ... + 18038.

It is an arithmetic number, because the mean of its divisors is an integer number (126133).

2⁷²⁰⁷⁴⁰ is an apocalyptic number.

It is an amenable number.

720740 is an abundant number, since it is smaller than the sum of its proper divisors (792856).

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

720740 is a wasteful number, since it uses less digits than its factorization.

720740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36046 (or 36044 counting only the distinct ones).

The product of its (nonzero) digits is 392, while the sum is 20.

The square root of 720740 is about 848.9640746227. The cubic root of 720740 is about 89.6587903389.

Adding to 720740 its reverse (47027), we get a palindrome (767767).

The spelling of 720740 in words is "seven hundred twenty thousand, seven hundred forty", and thus it is an iban number.