644959449 has 16 divisors (see below), whose sum is σ = 988444800. Its totient is φ = 415145808.

The previous prime is 644959429. The next prime is 644959459. The reversal of 644959449 is 944959446.

It is a happy number.

644959449 is a `hidden beast` number, since 6 + 4 + 4 + 9 + 594 + 49 = 666.

644959449 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 644959449 - 2⁵ = 644959417 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 644959395 and 644959404.

It is not an unprimeable number, because it can be changed into a prime (644959409) 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, 411069 + ... + 412634.

It is an arithmetic number, because the mean of its divisors is an integer number (61777800).

Almost surely, 2^644959449 is an apocalyptic number.

It is an amenable number.

644959449 is a deficient number, since it is larger than the sum of its proper divisors (343485351).

644959449 is a wasteful number, since it uses less digits than its factorization.

644959449 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 823741 (or 823735 counting only the distinct ones).

The product of its digits is 5598720, while the sum is 54.

The square root of 644959449 is about 25396.0518388194. The cubic root of 644959449 is about 863.9941526418.

The spelling of 644959449 in words is "six hundred forty-four million, nine hundred fifty-nine thousand, four hundred forty-nine".