644355614 has 16 divisors (see below), whose sum is σ = 1107401568. Its totient is φ = 275454432.

The previous prime is 644355587. The next prime is 644355619. The reversal of 644355614 is 416553446.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644355619) 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 7 ways as a sum of consecutive naturals, for example, 52409 + ... + 63524.

It is an arithmetic number, because the mean of its divisors is an integer number (69212598).

Almost surely, 2^644355614 is an apocalyptic number.

644355614 is a deficient number, since it is larger than the sum of its proper divisors (463045954).

644355614 is a wasteful number, since it uses less digits than its factorization.

644355614 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 116339.

The product of its digits is 172800, while the sum is 38.

The square root of 644355614 is about 25384.1606912657. The cubic root of 644355614 is about 863.7244339747.

The spelling of 644355614 in words is "six hundred forty-four million, three hundred fifty-five thousand, six hundred fourteen".