720807321 has 8 divisors (see below), whose sum is σ = 1035005440. Its totient is φ = 443573712.

The previous prime is 720807277. The next prime is 720807337. The reversal of 720807321 is 123708027.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 720807321 - 2⁹ = 720806809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (720807391) 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 7 ways as a sum of consecutive naturals, for example, 9241081 + ... + 9241158.

It is an arithmetic number, because the mean of its divisors is an integer number (129375680).

Almost surely, 2^720807321 is an apocalyptic number.

It is an amenable number.

720807321 is a deficient number, since it is larger than the sum of its proper divisors (314198119).

720807321 is a wasteful number, since it uses less digits than its factorization.

720807321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18482255.

The product of its (nonzero) digits is 4704, while the sum is 30.

The square root of 720807321 is about 26847.8550539889. The cubic root of 720807321 is about 896.6158179009.

It can be divided in two parts, 72080 and 7321, that added together give a triangular number (79401 = T₃₉₈).

The spelling of 720807321 in words is "seven hundred twenty million, eight hundred seven thousand, three hundred twenty-one".