720605645 has 16 divisors (see below), whose sum is σ = 898110720. Its totient is φ = 554645184.

The previous prime is 720605629. The next prime is 720605687. The reversal of 720605645 is 546506027.

It is a cyclic number.

It is not a de Polignac number, because 720605645 - 2⁴ = 720605629 is a prime.

It is a super-3 number, since 3×720605645³ (a number of 28 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 12122 + ... + 39851.

It is an arithmetic number, because the mean of its divisors is an integer number (56131920).

Almost surely, 2^720605645 is an apocalyptic number.

It is an amenable number.

720605645 is a deficient number, since it is larger than the sum of its proper divisors (177505075).

720605645 is a wasteful number, since it uses less digits than its factorization.

720605645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52084.

The product of its (nonzero) digits is 50400, while the sum is 35.

The square root of 720605645 is about 26844.0988859749. The cubic root of 720605645 is about 896.5321881737.

The spelling of 720605645 in words is "seven hundred twenty million, six hundred five thousand, six hundred forty-five".