644353347 has 16 divisors (see below), whose sum is σ = 941380992. Its totient is φ = 388792320.

The previous prime is 644353343. The next prime is 644353351. The reversal of 644353347 is 743353446.

It is an interprime number because it is at equal distance from previous prime (644353343) and next prime (644353351).

It is not a de Polignac number, because 644353347 - 2² = 644353343 is a prime.

It is not an unprimeable number, because it can be changed into a prime (644353343) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 35518 + ... + 50499.

It is an arithmetic number, because the mean of its divisors is an integer number (58836312).

Almost surely, 2^644353347 is an apocalyptic number.

644353347 is a deficient number, since it is larger than the sum of its proper divisors (297027645).

644353347 is a wasteful number, since it uses less digits than its factorization.

644353347 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86258.

The product of its digits is 362880, while the sum is 39.

The square root of 644353347 is about 25384.1160373963. The cubic root of 644353347 is about 863.7234210425.

Subtracting 644353347 from its reverse (743353446), we obtain a palindrome (99000099).

The spelling of 644353347 in words is "six hundred forty-four million, three hundred fifty-three thousand, three hundred forty-seven".