644244029 has 16 divisors (see below), whose sum is σ = 775341504. Its totient is φ = 527433600.

The previous prime is 644243921. The next prime is 644244047. The reversal of 644244029 is 920442446.

644244029 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-644244029 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 644244029.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644244049) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 49079 + ... + 60804.

It is an arithmetic number, because the mean of its divisors is an integer number (48458844).

Almost surely, 2^644244029 is an apocalyptic number.

It is an amenable number.

644244029 is a deficient number, since it is larger than the sum of its proper divisors (131097475).

644244029 is a wasteful number, since it uses less digits than its factorization.

644244029 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 109948.

The product of its (nonzero) digits is 55296, while the sum is 35.

The square root of 644244029 is about 25381.9626703689. The cubic root of 644244029 is about 863.6745731769.

The spelling of 644244029 in words is "six hundred forty-four million, two hundred forty-four thousand, twenty-nine".