720018 has 48 divisors (see below), whose sum is σ = 1788696. Its totient is φ = 207360.

The previous prime is 720007. The next prime is 720019. The reversal of 720018 is 810027.

It can be written as a sum of positive squares in 4 ways, for example, as 363609 + 356409 = 603^2 + 597^2 .

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

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (720019) by changing a digit.

720018 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 (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3888 + ... + 4068.

2⁷²⁰⁰¹⁸ is an apocalyptic number.

720018 is a gapful number since it is divisible by the number (78) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 720018, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (894348).

720018 is an abundant number, since it is smaller than the sum of its proper divisors (1068678).

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

720018 is a wasteful number, since it uses less digits than its factorization.

720018 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 219 (or 216 counting only the distinct ones).

The product of its (nonzero) digits is 112, while the sum is 18.

The square root of 720018 is about 848.5387439593. The cubic root of 720018 is about 89.6288418257.

Subtracting 720018 from its reverse (810027), we obtain a palindrome (90009).

It can be divided in two parts, 7200 and 18, that multiplied together give a square (129600 = 360²).

The spelling of 720018 in words is "seven hundred twenty thousand, eighteen".