644134634351 has 16 divisors (see below), whose sum is σ = 706898041920. Its totient is φ = 583263033600.

The previous prime is 644134634279. The next prime is 644134634371. The reversal of 644134634351 is 153436431446.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-644134634351 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 (644134634371) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3916310 + ... + 4077468.

It is an arithmetic number, because the mean of its divisors is an integer number (44181127620).

Almost surely, 2^644134634351 is an apocalyptic number.

644134634351 is a deficient number, since it is larger than the sum of its proper divisors (62763407569).

644134634351 is a wasteful number, since it uses less digits than its factorization.

644134634351 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 167026.

The product of its digits is 1244160, while the sum is 44.

The spelling of 644134634351 in words is "six hundred forty-four billion, one hundred thirty-four million, six hundred thirty-four thousand, three hundred fifty-one".