720635605 has 4 divisors (see below), whose sum is σ = 864762732. Its totient is φ = 576508480.

The previous prime is 720635599. The next prime is 720635623. The reversal of 720635605 is 506536027.

720635605 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 506536027 = 193 ⋅2624539.

It can be written as a sum of positive squares in 2 ways, for example, as 320875569 + 399760036 = 17913^2 + 19994^2 .

It is not a de Polignac number, because 720635605 - 2¹⁹ = 720111317 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 72063556 + ... + 72063565.

It is an arithmetic number, because the mean of its divisors is an integer number (216190683).

Almost surely, 2^720635605 is an apocalyptic number.

It is an amenable number.

720635605 is a deficient number, since it is larger than the sum of its proper divisors (144127127).

720635605 is a wasteful number, since it uses less digits than its factorization.

720635605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 144127126.

The product of its (nonzero) digits is 37800, while the sum is 34.

The square root of 720635605 is about 26844.6569171595. The cubic root of 720635605 is about 896.5446127836.

The spelling of 720635605 in words is "seven hundred twenty million, six hundred thirty-five thousand, six hundred five".