644326077 has 8 divisors (see below), whose sum is σ = 862272640. Its totient is φ = 427965120.

The previous prime is 644326057. The next prime is 644326087. The reversal of 644326077 is 770623446.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 644326077 - 2⁶ = 644326013 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644326037) 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 7 ways as a sum of consecutive naturals, for example, 395452 + ... + 397077.

It is an arithmetic number, because the mean of its divisors is an integer number (107784080).

Almost surely, 2^644326077 is an apocalyptic number.

It is an amenable number.

644326077 is a deficient number, since it is larger than the sum of its proper divisors (217946563).

644326077 is a wasteful number, since it uses less digits than its factorization.

644326077 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 792803.

The product of its (nonzero) digits is 169344, while the sum is 39.

The square root of 644326077 is about 25383.5788847830. The cubic root of 644326077 is about 863.7112361805.

The spelling of 644326077 in words is "six hundred forty-four million, three hundred twenty-six thousand, seventy-seven".