644714057 has 8 divisors (see below), whose sum is σ = 694860936. Its totient is φ = 594646272.

The previous prime is 644714047. The next prime is 644714071. The reversal of 644714057 is 750417446.

It is a happy number.

644714057 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 185940496 + 458773561 = 13636^2 + 21419^2 .

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 644714057 - 2⁴ = 644714041 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 644714057.

It is not an unprimeable number, because it can be changed into a prime (644714047) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2258 + ... + 35979.

It is an arithmetic number, because the mean of its divisors is an integer number (86857617).

Almost surely, 2^644714057 is an apocalyptic number.

It is an amenable number.

644714057 is a deficient number, since it is larger than the sum of its proper divisors (50146879).

644714057 is a wasteful number, since it uses less digits than its factorization.

644714057 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39547.

The product of its (nonzero) digits is 94080, while the sum is 38.

The square root of 644714057 is about 25391.2200770266. The cubic root of 644714057 is about 863.8845622128.

The spelling of 644714057 in words is "six hundred forty-four million, seven hundred fourteen thousand, fifty-seven".