644311047 has 8 divisors (see below), whose sum is σ = 860963056. Its totient is φ = 428599872.

The previous prime is 644311039. The next prime is 644311051. The reversal of 644311047 is 740113446.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 644311047 - 2³ = 644311039 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 (644319047) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 233608 + ... + 236349.

It is an arithmetic number, because the mean of its divisors is an integer number (107620382).

Almost surely, 2^644311047 is an apocalyptic number.

644311047 is a deficient number, since it is larger than the sum of its proper divisors (216652009).

644311047 is a wasteful number, since it uses less digits than its factorization.

644311047 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 470417.

The product of its (nonzero) digits is 8064, while the sum is 30.

The square root of 644311047 is about 25383.2828255133. The cubic root of 644311047 is about 863.7045202844.

The spelling of 644311047 in words is "six hundred forty-four million, three hundred eleven thousand, forty-seven".