644159 has 2 divisors, whose sum is σ = 644160. Its totient is φ = 644158.

The previous prime is 644153. The next prime is 644173. The reversal of 644159 is 951446.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 644159 - 2⁴ = 644143 is a prime.

It is an Ulam number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (644153) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322079 + 322080.

It is an arithmetic number, because the mean of its divisors is an integer number (322080).

2⁶⁴⁴¹⁵⁹ is an apocalyptic number.

644159 is a deficient number, since it is larger than the sum of its proper divisors (1).

644159 is an equidigital number, since it uses as much as digits as its factorization.

644159 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4320, while the sum is 29.

The square root of 644159 is about 802.5951656969. The cubic root of 644159 is about 86.3636574834.

The spelling of 644159 in words is "six hundred forty-four thousand, one hundred fifty-nine".