644582677 has 4 divisors (see below), whose sum is σ = 644789376. Its totient is φ = 644375980.

The previous prime is 644582633. The next prime is 644582711. The reversal of 644582677 is 776285446.

644582677 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 644582677 - 2¹⁵ = 644549909 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 644582677.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644582377) 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, 98599 + ... + 104932.

It is an arithmetic number, because the mean of its divisors is an integer number (161197344).

Almost surely, 2^644582677 is an apocalyptic number.

It is an amenable number.

644582677 is a deficient number, since it is larger than the sum of its proper divisors (206699).

644582677 is a wasteful number, since it uses less digits than its factorization.

644582677 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 206698.

The product of its digits is 2257920, while the sum is 49.

The square root of 644582677 is about 25388.6328304617. The cubic root of 644582677 is about 863.8258773520.

The spelling of 644582677 in words is "six hundred forty-four million, five hundred eighty-two thousand, six hundred seventy-seven".