644326047 has 12 divisors (see below), whose sum is σ = 932114040. Its totient is φ = 428894928.

The previous prime is 644326037. The next prime is 644326051. The reversal of 644326047 is 740623446.

644326047 is a `hidden beast` number, since 6 + 4 + 43 + 2 + 604 + 7 = 666.

It is not a de Polignac number, because 644326047 - 2⁷ = 644325919 is a prime.

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 11 ways as a sum of consecutive naturals, for example, 48388 + ... + 60249.

It is an arithmetic number, because the mean of its divisors is an integer number (77676170).

Almost surely, 2^644326047 is an apocalyptic number.

644326047 is a deficient number, since it is larger than the sum of its proper divisors (287787993).

644326047 is a wasteful number, since it uses less digits than its factorization.

644326047 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 109302 (or 109299 counting only the distinct ones).

The product of its (nonzero) digits is 96768, while the sum is 36.

The square root of 644326047 is about 25383.5782938497. The cubic root of 644326047 is about 863.7112227756.

The spelling of 644326047 in words is "six hundred forty-four million, three hundred twenty-six thousand, forty-seven".