645120205 has 16 divisors (see below), whose sum is σ = 816822720. Its totient is φ = 487772928.

The previous prime is 645120193. The next prime is 645120211. The reversal of 645120205 is 502021546.

645120205 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 645120205 - 2¹¹ = 645118157 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 645120205.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33294 + ... + 48976.

It is an arithmetic number, because the mean of its divisors is an integer number (51051420).

Almost surely, 2^645120205 is an apocalyptic number.

It is an amenable number.

645120205 is a deficient number, since it is larger than the sum of its proper divisors (171702515).

645120205 is a wasteful number, since it uses less digits than its factorization.

645120205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16140.

The product of its (nonzero) digits is 2400, while the sum is 25.

The square root of 645120205 is about 25399.2166217779. The cubic root of 645120205 is about 864.0659301291.

The spelling of 645120205 in words is "six hundred forty-five million, one hundred twenty thousand, two hundred five".