644446677 has 12 divisors (see below), whose sum is σ = 999550176. Its totient is φ = 368255160.

The previous prime is 644446661. The next prime is 644446679. The reversal of 644446677 is 776644446.

It is not a de Polignac number, because 644446677 - 2⁴ = 644446661 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644446679) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 2191849 + ... + 2192142.

It is an arithmetic number, because the mean of its divisors is an integer number (83295848).

Almost surely, 2^644446677 is an apocalyptic number.

It is an amenable number.

644446677 is a deficient number, since it is larger than the sum of its proper divisors (355103499).

644446677 is a wasteful number, since it uses less digits than its factorization.

644446677 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4384008 (or 4384001 counting only the distinct ones).

The product of its digits is 2709504, while the sum is 48.

The square root of 644446677 is about 25385.9543251775. The cubic root of 644446677 is about 863.7651204277.

The spelling of 644446677 in words is "six hundred forty-four million, four hundred forty-six thousand, six hundred seventy-seven".