645220736288 has 54 divisors (see below), whose sum is σ = 1280204239419. Its totient is φ = 320108948992.

The previous prime is 645220736267. The next prime is 645220736417. The reversal of 645220736288 is 882637022546.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It can be written as a sum of positive squares in 5 ways, for example, as 44391118864 + 600829617424 = 210692^2 + 775132^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=567988.

It is a Duffinian 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 8 ways as a sum of consecutive naturals, for example, 677041220 + ... + 677042172.

Almost surely, 2^645220736288 is an apocalyptic number.

It is an amenable number.

645220736288 is a deficient number, since it is larger than the sum of its proper divisors (634983503131).

645220736288 is an frugal number, since it uses more digits than its factorization.

645220736288 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2214 (or 1104 counting only the distinct ones).

The product of its (nonzero) digits is 7741440, while the sum is 53.

The spelling of 645220736288 in words is "six hundred forty-five billion, two hundred twenty million, seven hundred thirty-six thousand, two hundred eighty-eight".