645596555 has 4 divisors (see below), whose sum is σ = 774715872. Its totient is φ = 516477240.

The previous prime is 645596543. The next prime is 645596557. The reversal of 645596555 is 555695546.

645596555 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.

It is not a de Polignac number, because 645596555 - 2⁶ = 645596491 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645596557) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64559651 + ... + 64559660.

It is an arithmetic number, because the mean of its divisors is an integer number (193678968).

Almost surely, 2^645596555 is an apocalyptic number.

645596555 is a deficient number, since it is larger than the sum of its proper divisors (129119317).

645596555 is a wasteful number, since it uses less digits than its factorization.

645596555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129119316.

The product of its digits is 4050000, while the sum is 50.

The square root of 645596555 is about 25408.5921491137. The cubic root of 645596555 is about 864.2785502153.

The spelling of 645596555 in words is "six hundred forty-five million, five hundred ninety-six thousand, five hundred fifty-five".