720390 has 64 divisors (see below), whose sum is σ = 1969920. Its totient is φ = 167040.

The previous prime is 720373. The next prime is 720397. The reversal of 720390 is 93027.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (720397) by changing a digit.

720390 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 31 ways as a sum of consecutive naturals, for example, 12181 + ... + 12239.

It is an arithmetic number, because the mean of its divisors is an integer number (30780).

2⁷²⁰³⁹⁰ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 720390, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (984960).

720390 is an abundant number, since it is smaller than the sum of its proper divisors (1249530).

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

720390 is a wasteful number, since it uses less digits than its factorization.

720390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117.

The product of its (nonzero) digits is 378, while the sum is 21.

The square root of 720390 is about 848.7579160161. The cubic root of 720390 is about 89.6442748606.

The spelling of 720390 in words is "seven hundred twenty thousand, three hundred ninety".