720755665 has 16 divisors (see below), whose sum is σ = 992125440. Its totient is φ = 492402240.

The previous prime is 720755663. The next prime is 720755677. The reversal of 720755665 is 566557027.

It is not a de Polignac number, because 720755665 - 2¹ = 720755663 is a prime.

It is a super-3 number, since 3×720755665³ (a number of 28 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (720755663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 28510 + ... + 47479.

It is an arithmetic number, because the mean of its divisors is an integer number (62007840).

Almost surely, 2^720755665 is an apocalyptic number.

It is an amenable number.

720755665 is a deficient number, since it is larger than the sum of its proper divisors (271369775).

720755665 is a wasteful number, since it uses less digits than its factorization.

720755665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76272.

The product of its (nonzero) digits is 441000, while the sum is 43.

The square root of 720755665 is about 26846.8930232159. The cubic root of 720755665 is about 896.5943990039.

The spelling of 720755665 in words is "seven hundred twenty million, seven hundred fifty-five thousand, six hundred sixty-five".