644147 has 8 divisors (see below), whose sum is σ = 779616. Its totient is φ = 519552.

The previous prime is 644143. The next prime is 644153. The reversal of 644147 is 741446.

644147 is digitally balanced in base 2, 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 a cyclic number.

It is not a de Polignac number, because 644147 - 2² = 644143 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (644141) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2588 + ... + 2825.

It is an arithmetic number, because the mean of its divisors is an integer number (97452).

2⁶⁴⁴¹⁴⁷ is an apocalyptic number.

644147 is a deficient number, since it is larger than the sum of its proper divisors (135469).

644147 is a wasteful number, since it uses less digits than its factorization.

644147 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5437.

The product of its digits is 2688, while the sum is 26.

The square root of 644147 is about 802.5876899131. The cubic root of 644147 is about 86.3631211923.

The spelling of 644147 in words is "six hundred forty-four thousand, one hundred forty-seven".