644329 has 8 divisors (see below), whose sum is σ = 745920. Its totient is φ = 545136.

The previous prime is 644327. The next prime is 644341. The reversal of 644329 is 923446.

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

It is a cyclic number.

It is not a de Polignac number, because 644329 - 2¹ = 644327 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 644297 and 644306.

It is not an unprimeable number, because it can be changed into a prime (644327) 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 7 ways as a sum of consecutive naturals, for example, 27 + ... + 1135.

It is an arithmetic number, because the mean of its divisors is an integer number (93240).

2⁶⁴⁴³²⁹ is an apocalyptic number.

It is an amenable number.

644329 is a deficient number, since it is larger than the sum of its proper divisors (101591).

644329 is a wasteful number, since it uses less digits than its factorization.

644329 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1199.

The product of its digits is 5184, while the sum is 28.

The square root of 644329 is about 802.7010651544. The cubic root of 644329 is about 86.3712542260.

The spelling of 644329 in words is "six hundred forty-four thousand, three hundred twenty-nine".