644305774 has 16 divisors (see below), whose sum is σ = 1106841600. Its totient is φ = 275551704.

The previous prime is 644305747. The next prime is 644305801. The reversal of 644305774 is 477503446.

It is an interprime number because it is at equal distance from previous prime (644305747) and next prime (644305801).

It is a super-3 number, since 3×644305774³ (a number of 27 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 41334 + ... + 54745.

It is an arithmetic number, because the mean of its divisors is an integer number (69177600).

Almost surely, 2^644305774 is an apocalyptic number.

644305774 is a deficient number, since it is larger than the sum of its proper divisors (462535826).

644305774 is a wasteful number, since it uses less digits than its factorization.

644305774 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 96567.

The product of its (nonzero) digits is 282240, while the sum is 40.

The square root of 644305774 is about 25383.1789577271. The cubic root of 644305774 is about 863.7021641107.

The spelling of 644305774 in words is "six hundred forty-four million, three hundred five thousand, seven hundred seventy-four".