720636 has 48 divisors (see below), whose sum is σ = 2010624. Its totient is φ = 196416.

The previous prime is 720619. The next prime is 720653. The reversal of 720636 is 636027.

It is an interprime number because it is at equal distance from previous prime (720619) and next prime (720653).

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 720636.

It is an unprimeable number.

720636 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1746 + ... + 2118.

It is an arithmetic number, because the mean of its divisors is an integer number (41888).

2⁷²⁰⁶³⁶ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 720636, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1005312).

720636 is an abundant number, since it is smaller than the sum of its proper divisors (1289988).

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

720636 is a wasteful number, since it uses less digits than its factorization.

720636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 410 (or 408 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 24.

The square root of 720636 is about 848.9028212935. The cubic root of 720636 is about 89.6544776590.

The spelling of 720636 in words is "seven hundred twenty thousand, six hundred thirty-six".