644612017 has 4 divisors (see below), whose sum is σ = 736699456. Its totient is φ = 552524580.

The previous prime is 644611937. The next prime is 644612063. The reversal of 644612017 is 710216446.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 644612017 - 2⁷ = 644611889 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 644612017.

It is not an unprimeable number, because it can be changed into a prime (644612077) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 46043709 + ... + 46043722.

It is an arithmetic number, because the mean of its divisors is an integer number (184174864).

Almost surely, 2^644612017 is an apocalyptic number.

It is an amenable number.

644612017 is a deficient number, since it is larger than the sum of its proper divisors (92087439).

644612017 is an equidigital number, since it uses as much as digits as its factorization.

644612017 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92087438.

The product of its (nonzero) digits is 8064, while the sum is 31.

The square root of 644612017 is about 25389.2106415304. The cubic root of 644612017 is about 863.8389836442.

The spelling of 644612017 in words is "six hundred forty-four million, six hundred twelve thousand, seventeen".