644497347 has 32 divisors (see below), whose sum is σ = 1005598720. Its totient is φ = 363605760.

The previous prime is 644497333. The next prime is 644497351. The reversal of 644497347 is 743794446.

It is not a de Polignac number, because 644497347 - 2⁷ = 644497219 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 644497296 and 644497305.

It is not an unprimeable number, because it can be changed into a prime (643497347) 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 31 ways as a sum of consecutive naturals, for example, 8943 + ... + 36999.

It is an arithmetic number, because the mean of its divisors is an integer number (31424960).

Almost surely, 2^644497347 is an apocalyptic number.

644497347 is a deficient number, since it is larger than the sum of its proper divisors (361101373).

644497347 is a wasteful number, since it uses less digits than its factorization.

644497347 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28123.

The product of its digits is 2032128, while the sum is 48.

The square root of 644497347 is about 25386.9522983756. The cubic root of 644497347 is about 863.7877578484.

The spelling of 644497347 in words is "six hundred forty-four million, four hundred ninety-seven thousand, three hundred forty-seven".