644914 has 8 divisors (see below), whose sum is σ = 990000. Its totient is φ = 314916.

The previous prime is 644911. The next prime is 644923. The reversal of 644914 is 419446.

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

It is a d-powerful number, because it can be written as 6⁶ + 4⁴ + 9⁶ + 4⁵ + 1 + 4⁸ .

It is not an unprimeable number, because it can be changed into a prime (644911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3664 + ... + 3835.

It is an arithmetic number, because the mean of its divisors is an integer number (123750).

2⁶⁴⁴⁹¹⁴ is an apocalyptic number.

644914 is a deficient number, since it is larger than the sum of its proper divisors (345086).

644914 is a wasteful number, since it uses less digits than its factorization.

644914 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7544.

The product of its digits is 3456, while the sum is 28.

The square root of 644914 is about 803.0653771643. The cubic root of 644914 is about 86.3973857519.

The spelling of 644914 in words is "six hundred forty-four thousand, nine hundred fourteen".