644127347 has 4 divisors (see below), whose sum is σ = 653741256. Its totient is φ = 634513440.

The previous prime is 644127329. The next prime is 644127349. The reversal of 644127347 is 743721446.

644127347 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 a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-644127347 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 644127347.

It is not an unprimeable number, because it can be changed into a prime (644127349) 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, 4806854 + ... + 4806987.

It is an arithmetic number, because the mean of its divisors is an integer number (163435314).

Almost surely, 2^644127347 is an apocalyptic number.

644127347 is a gapful number since it is divisible by the number (67) formed by its first and last digit.

644127347 is a deficient number, since it is larger than the sum of its proper divisors (9613909).

644127347 is an equidigital number, since it uses as much as digits as its factorization.

644127347 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9613908.

The product of its digits is 112896, while the sum is 38.

The square root of 644127347 is about 25379.6640442698. The cubic root of 644127347 is about 863.6224286703.

The spelling of 644127347 in words is "six hundred forty-four million, one hundred twenty-seven thousand, three hundred forty-seven".