645664201 has 16 divisors (see below), whose sum is σ = 796870144. Its totient is φ = 509436864.

The previous prime is 645664189. The next prime is 645664219. The reversal of 645664201 is 102466546.

645664201 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 645664201 - 2¹³ = 645656009 is a prime.

It is not an unprimeable number, because it can be changed into a prime (645664501) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23731 + ... + 43063.

It is an arithmetic number, because the mean of its divisors is an integer number (49804384).

Almost surely, 2^645664201 is an apocalyptic number.

It is an amenable number.

645664201 is a deficient number, since it is larger than the sum of its proper divisors (151205943).

645664201 is a wasteful number, since it uses less digits than its factorization.

645664201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19720.

The product of its (nonzero) digits is 34560, while the sum is 34.

The square root of 645664201 is about 25409.9232781211. The cubic root of 645664201 is about 864.3087357052.

The spelling of 645664201 in words is "six hundred forty-five million, six hundred sixty-four thousand, two hundred one".