644805914 has 8 divisors (see below), whose sum is σ = 967351188. Its totient is φ = 322355520.

The previous prime is 644805913. The next prime is 644805947. The reversal of 644805914 is 419508446.

It can be written as a sum of positive squares in 2 ways, for example, as 641760889 + 3045025 = 25333^2 + 1745^2 .

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

It is not an unprimeable number, because it can be changed into a prime (644805913) 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 3 ways as a sum of consecutive naturals, for example, 3167 + ... + 36050.

Almost surely, 2^644805914 is an apocalyptic number.

644805914 is a deficient number, since it is larger than the sum of its proper divisors (322545274).

644805914 is a wasteful number, since it uses less digits than its factorization.

644805914 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47440.

The product of its (nonzero) digits is 138240, while the sum is 41.

The square root of 644805914 is about 25393.0288465161. The cubic root of 644805914 is about 863.9255881917.

The spelling of 644805914 in words is "six hundred forty-four million, eight hundred five thousand, nine hundred fourteen".