644883 has 8 divisors (see below), whose sum is σ = 868608. Its totient is φ = 425544.

The previous prime is 644881. The next prime is 644899. The reversal of 644883 is 388446.

644883 is digitally balanced in base 7, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 644883 - 2¹ = 644881 is a prime.

644883 is strictly pandigital in base 7.

It is not an unprimeable number, because it can be changed into a prime (644881) 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, 735 + ... + 1352.

It is an arithmetic number, because the mean of its divisors is an integer number (108576).

2⁶⁴⁴⁸⁸³ is an apocalyptic number.

644883 is a deficient number, since it is larger than the sum of its proper divisors (223725).

644883 is a wasteful number, since it uses less digits than its factorization.

644883 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2193.

The product of its digits is 18432, while the sum is 33.

The square root of 644883 is about 803.0460758886. The cubic root of 644883 is about 86.3960014010.

The spelling of 644883 in words is "six hundred forty-four thousand, eight hundred eighty-three".