644096811 has 8 divisors (see below), whose sum is σ = 861965824. Its totient is φ = 427812840.

The previous prime is 644096809. The next prime is 644096813. The reversal of 644096811 is 118690446.

It is an interprime number because it is at equal distance from previous prime (644096809) and next prime (644096813).

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

It is not a de Polignac number, because 644096811 - 2¹ = 644096809 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 644096811.

It is not an unprimeable number, because it can be changed into a prime (644096813) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 395311 + ... + 396936.

It is an arithmetic number, because the mean of its divisors is an integer number (107745728).

Almost surely, 2^644096811 is an apocalyptic number.

644096811 is a deficient number, since it is larger than the sum of its proper divisors (217869013).

644096811 is a wasteful number, since it uses less digits than its factorization.

644096811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 792521.

The product of its (nonzero) digits is 41472, while the sum is 39.

The square root of 644096811 is about 25379.0624531325. The cubic root of 644096811 is about 863.6087812700.

The spelling of 644096811 in words is "six hundred forty-four million, ninety-six thousand, eight hundred eleven".