647720717 has 8 divisors (see below), whose sum is σ = 750678912. Its totient is φ = 547369200.

The previous prime is 647720707. The next prime is 647720767. The reversal of 647720717 is 717027746.

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

It is not a de Polignac number, because 647720717 - 2¹⁰ = 647719693 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (647720707) 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, 651134 + ... + 652127.

It is an arithmetic number, because the mean of its divisors is an integer number (93834864).

Almost surely, 2^647720717 is an apocalyptic number.

It is an amenable number.

647720717 is a deficient number, since it is larger than the sum of its proper divisors (102958195).

647720717 is a wasteful number, since it uses less digits than its factorization.

647720717 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1303339.

The product of its (nonzero) digits is 115248, while the sum is 41.

The square root of 647720717 is about 25450.3578953224. The cubic root of 647720717 is about 865.2254046326.

The spelling of 647720717 in words is "six hundred forty-seven million, seven hundred twenty thousand, seven hundred seventeen".