645765211 has 16 divisors (see below), whose sum is σ = 814177728. Its totient is φ = 498470400.

The previous prime is 645765199. The next prime is 645765259. The reversal of 645765211 is 112567546.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 645765211 - 2¹⁷ = 645634139 is a prime.

It is not an unprimeable number, because it can be changed into a prime (645765611) by changing a digit.

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, 82810 + ... + 90271.

It is an arithmetic number, because the mean of its divisors is an integer number (50886108).

Almost surely, 2^645765211 is an apocalyptic number.

645765211 is a deficient number, since it is larger than the sum of its proper divisors (168412517).

645765211 is a wasteful number, since it uses less digits than its factorization.

645765211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 173142.

The product of its digits is 50400, while the sum is 37.

The square root of 645765211 is about 25411.9108096971. The cubic root of 645765211 is about 864.3538051975.

The spelling of 645765211 in words is "six hundred forty-five million, seven hundred sixty-five thousand, two hundred eleven".