644844246 has 8 divisors (see below), whose sum is σ = 1289688504. Its totient is φ = 214948080.

The previous prime is 644844241. The next prime is 644844257. The reversal of 644844246 is 642448446.

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

644844246 is an admirable number.

It is a junction number, because it is equal to n+sod(n) for n = 644844198 and 644844207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644844241) 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, 53737015 + ... + 53737026.

It is an arithmetic number, because the mean of its divisors is an integer number (161211063).

Almost surely, 2^644844246 is an apocalyptic number.

644844246 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

644844246 is a wasteful number, since it uses less digits than its factorization.

644844246 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107474046.

The product of its digits is 589824, while the sum is 42.

The square root of 644844246 is about 25393.7836093797. The cubic root of 644844246 is about 863.9427072135.

The spelling of 644844246 in words is "six hundred forty-four million, eight hundred forty-four thousand, two hundred forty-six".