644086 has 8 divisors (see below), whose sum is σ = 970200. Its totient is φ = 320688.

The previous prime is 644057. The next prime is 644089. The reversal of 644086 is 680446.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644089) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 90 + ... + 1138.

It is an arithmetic number, because the mean of its divisors is an integer number (121275).

2⁶⁴⁴⁰⁸⁶ is an apocalyptic number.

644086 is a deficient number, since it is larger than the sum of its proper divisors (326114).

644086 is a wasteful number, since it uses less digits than its factorization.

644086 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1358.

The product of its (nonzero) digits is 4608, while the sum is 28.

The square root of 644086 is about 802.5496869353. The cubic root of 644086 is about 86.3603949426.

The spelling of 644086 in words is "six hundred forty-four thousand, eighty-six".