720565617 has 4 divisors (see below), whose sum is σ = 960754160. Its totient is φ = 480377076.

The previous prime is 720565609. The next prime is 720565673. The reversal of 720565617 is 716565027.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 720565617 - 2³ = 720565609 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (720565607) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 120094267 + ... + 120094272.

It is an arithmetic number, because the mean of its divisors is an integer number (240188540).

Almost surely, 2^720565617 is an apocalyptic number.

It is an amenable number.

720565617 is a deficient number, since it is larger than the sum of its proper divisors (240188543).

720565617 is a wasteful number, since it uses less digits than its factorization.

720565617 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 240188542.

The product of its (nonzero) digits is 88200, while the sum is 39.

The square root of 720565617 is about 26843.3533113879. The cubic root of 720565617 is about 896.5155877602.

The spelling of 720565617 in words is "seven hundred twenty million, five hundred sixty-five thousand, six hundred seventeen".