644635846 has 8 divisors (see below), whose sum is σ = 975511224. Its totient is φ = 319465440.

The previous prime is 644635799. The next prime is 644635847. The reversal of 644635846 is 648536446.

644635846 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a junction number, because it is equal to n+sod(n) for n = 644635796 and 644635805.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644635847) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1425960 + ... + 1426411.

It is an arithmetic number, because the mean of its divisors is an integer number (121938903).

Almost surely, 2^644635846 is an apocalyptic number.

644635846 is a deficient number, since it is larger than the sum of its proper divisors (330875378).

644635846 is a wasteful number, since it uses less digits than its factorization.

644635846 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2852486.

The product of its digits is 1658880, while the sum is 46.

The square root of 644635846 is about 25389.6799113341. The cubic root of 644635846 is about 863.8496278585.

The spelling of 644635846 in words is "six hundred forty-four million, six hundred thirty-five thousand, eight hundred forty-six".