644304105 has 16 divisors (see below), whose sum is σ = 1145429760. Its totient is φ = 343628784.

The previous prime is 644304103. The next prime is 644304109. The reversal of 644304105 is 501403446.

644304105 is a `hidden beast` number, since 644 + 3 + 0 + 4 + 10 + 5 = 666.

It is not a de Polignac number, because 644304105 - 2¹ = 644304103 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (644304103) 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, 2386177 + ... + 2386446.

It is an arithmetic number, because the mean of its divisors is an integer number (71589360).

Almost surely, 2^644304105 is an apocalyptic number.

It is an amenable number.

644304105 is a deficient number, since it is larger than the sum of its proper divisors (501125655).

644304105 is a wasteful number, since it uses less digits than its factorization.

644304105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4772637 (or 4772631 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 27.

The square root of 644304105 is about 25383.1460816030. The cubic root of 644304105 is about 863.7014183363.

The spelling of 644304105 in words is "six hundred forty-four million, three hundred four thousand, one hundred five".