644144063 has 8 divisors (see below), whose sum is σ = 662352768. Its totient is φ = 625977504.

The previous prime is 644144057. The next prime is 644144069. The reversal of 644144063 is 360441446.

It is an interprime number because it is at equal distance from previous prime (644144057) and next prime (644144069).

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 644144063 - 2⁴ = 644144047 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644144069) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21845 + ... + 42017.

It is an arithmetic number, because the mean of its divisors is an integer number (82794096).

Almost surely, 2^644144063 is an apocalyptic number.

644144063 is a deficient number, since it is larger than the sum of its proper divisors (18208705).

644144063 is a wasteful number, since it uses less digits than its factorization.

644144063 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21073.

The product of its (nonzero) digits is 27648, while the sum is 32.

The square root of 644144063 is about 25379.9933609132. The cubic root of 644144063 is about 863.6298993398.

The spelling of 644144063 in words is "six hundred forty-four million, one hundred forty-four thousand, sixty-three".