644117450 has 12 divisors (see below), whose sum is σ = 1198058550. Its totient is φ = 257646960.

The previous prime is 644117447. The next prime is 644117459. The reversal of 644117450 is 54711446.

644117450 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 3 ways, for example, as 494128441 + 149989009 = 22229^2 + 12247^2 .

It is not an unprimeable number, because it can be changed into a prime (644117459) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6441125 + ... + 6441224.

Almost surely, 2^644117450 is an apocalyptic number.

644117450 is a deficient number, since it is larger than the sum of its proper divisors (553941100).

644117450 is a wasteful number, since it uses less digits than its factorization.

644117450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12882361 (or 12882356 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 32.

The square root of 644117450 is about 25379.4690645805. The cubic root of 644117450 is about 863.6180054689.

Adding to 644117450 its reverse (54711446), we get a palindrome (698828896).

The spelling of 644117450 in words is "six hundred forty-four million, one hundred seventeen thousand, four hundred fifty".