644072347 has 8 divisors (see below), whose sum is σ = 649715040. Its totient is φ = 638454720.

The previous prime is 644072329. The next prime is 644072383. The reversal of 644072347 is 743270446.

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

It is a cyclic number.

It is not a de Polignac number, because 644072347 - 2²⁷ = 509854619 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (644072147) 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, 47322 + ... + 59392.

It is an arithmetic number, because the mean of its divisors is an integer number (81214380).

Almost surely, 2^644072347 is an apocalyptic number.

644072347 is a deficient number, since it is larger than the sum of its proper divisors (5642693).

644072347 is a wasteful number, since it uses less digits than its factorization.

644072347 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12533.

The product of its (nonzero) digits is 112896, while the sum is 37.

The square root of 644072347 is about 25378.5804764569. The cubic root of 644072347 is about 863.5978473067.

It can be divided in two parts, 6440 and 72347, that added together give a palindrome (78787).

The spelling of 644072347 in words is "six hundred forty-four million, seventy-two thousand, three hundred forty-seven".