644458479 has 16 divisors (see below), whose sum is σ = 988061952. Its totient is φ = 366000768.

The previous prime is 644458447. The next prime is 644458483. The reversal of 644458479 is 974854446.

It is a happy number.

It is not a de Polignac number, because 644458479 - 2⁵ = 644458447 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644458439) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 90714 + ... + 97559.

It is an arithmetic number, because the mean of its divisors is an integer number (61753872).

Almost surely, 2^644458479 is an apocalyptic number.

644458479 is a deficient number, since it is larger than the sum of its proper divisors (343603473).

644458479 is a wasteful number, since it uses less digits than its factorization.

644458479 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 188446.

The product of its digits is 3870720, while the sum is 51.

The square root of 644458479 is about 25386.1867754888. The cubic root of 644458479 is about 863.7703932165.

The spelling of 644458479 in words is "six hundred forty-four million, four hundred fifty-eight thousand, four hundred seventy-nine".