720706009 has 4 divisors (see below), whose sum is σ = 721394100. Its totient is φ = 720017920.

The previous prime is 720705991. The next prime is 720706013. The reversal of 720706009 is 900607027.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 900607027 = 17761 ⋅50707.

It can be written as a sum of positive squares in 2 ways, for example, as 657153225 + 63552784 = 25635^2 + 7972^2 .

It is a cyclic number.

It is not a de Polignac number, because 720706009 - 2¹⁵ = 720673241 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (720704009) 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 3 ways as a sum of consecutive naturals, for example, 342472 + ... + 344569.

It is an arithmetic number, because the mean of its divisors is an integer number (180348525).

Almost surely, 2^720706009 is an apocalyptic number.

It is an amenable number.

720706009 is a deficient number, since it is larger than the sum of its proper divisors (688091).

720706009 is a wasteful number, since it uses less digits than its factorization.

720706009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 688090.

The product of its (nonzero) digits is 5292, while the sum is 31.

The square root of 720706009 is about 26845.9682075354. The cubic root of 720706009 is about 896.5738084321.

The spelling of 720706009 in words is "seven hundred twenty million, seven hundred six thousand, nine".