644614055 has 4 divisors (see below), whose sum is σ = 773536872. Its totient is φ = 515691240.

The previous prime is 644614051. The next prime is 644614129. The reversal of 644614055 is 550416446.

644614055 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.

It is not a de Polignac number, because 644614055 - 2² = 644614051 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 (644614051) 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, 64461401 + ... + 64461410.

It is an arithmetic number, because the mean of its divisors is an integer number (193384218).

Almost surely, 2^644614055 is an apocalyptic number.

644614055 is a deficient number, since it is larger than the sum of its proper divisors (128922817).

644614055 is a wasteful number, since it uses less digits than its factorization.

644614055 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128922816.

The product of its (nonzero) digits is 57600, while the sum is 35.

The square root of 644614055 is about 25389.2507766574. The cubic root of 644614055 is about 863.8398940119.

The spelling of 644614055 in words is "six hundred forty-four million, six hundred fourteen thousand, fifty-five".