644706500195 has 8 divisors (see below), whose sum is σ = 773732619744. Its totient is φ = 515708653824.

The previous prime is 644706500173. The next prime is 644706500219. The reversal of 644706500195 is 591005607446.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 644706500195 - 2²⁰ = 644705451619 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7018094 + ... + 7109363.

It is an arithmetic number, because the mean of its divisors is an integer number (96716577468).

Almost surely, 2^644706500195 is an apocalyptic number.

644706500195 is a deficient number, since it is larger than the sum of its proper divisors (129026119549).

644706500195 is a wasteful number, since it uses less digits than its factorization.

644706500195 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14136589.

The product of its (nonzero) digits is 907200, while the sum is 47.

The spelling of 644706500195 in words is "six hundred forty-four billion, seven hundred six million, five hundred thousand, one hundred ninety-five".