644404846 has 32 divisors (see below), whose sum is σ = 1038235968. Its totient is φ = 299270400.

The previous prime is 644404841. The next prime is 644404879. The reversal of 644404846 is 648404446.

It is a junction number, because it is equal to n+sod(n) for n = 644404799 and 644404808.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644404841) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 244930 + ... + 247546.

It is an arithmetic number, because the mean of its divisors is an integer number (32444874).

Almost surely, 2^644404846 is an apocalyptic number.

644404846 is a deficient number, since it is larger than the sum of its proper divisors (393831122).

644404846 is a wasteful number, since it uses less digits than its factorization.

644404846 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2796.

The product of its (nonzero) digits is 294912, while the sum is 40.

The square root of 644404846 is about 25385.1304113254. The cubic root of 644404846 is about 863.7464310405.

The spelling of 644404846 in words is "six hundred forty-four million, four hundred four thousand, eight hundred forty-six".