720217720 has 64 divisors (see below), whose sum is σ = 1669248000. Its totient is φ = 279547008.

The previous prime is 720217709. The next prime is 720217723. The reversal of 720217720 is 27712027.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (720217723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 184509 + ... + 188371.

It is an arithmetic number, because the mean of its divisors is an integer number (26082000).

Almost surely, 2^720217720 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 720217720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (834624000).

720217720 is an abundant number, since it is smaller than the sum of its proper divisors (949030280).

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

720217720 is a wasteful number, since it uses less digits than its factorization.

720217720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4012 (or 4008 counting only the distinct ones).

The product of its (nonzero) digits is 2744, while the sum is 28.

The square root of 720217720 is about 26836.8723960152. The cubic root of 720217720 is about 896.3712820070.

Adding to 720217720 its reverse (27712027), we get a palindrome (747929747).

The spelling of 720217720 in words is "seven hundred twenty million, two hundred seventeen thousand, seven hundred twenty".