644302465 has 16 divisors (see below), whose sum is σ = 820270800. Its totient is φ = 484157440.

The previous prime is 644302459. The next prime is 644302469. The reversal of 644302465 is 564203446.

It can be written as a sum of positive squares in 8 ways, for example, as 14493249 + 629809216 = 3807^2 + 25096^2 .

It is not a de Polignac number, because 644302465 - 2⁹ = 644301953 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 644302465.

It is not an unprimeable number, because it can be changed into a prime (644302469) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 37011 + ... + 51559.

It is an arithmetic number, because the mean of its divisors is an integer number (51266925).

Almost surely, 2^644302465 is an apocalyptic number.

It is an amenable number.

644302465 is a deficient number, since it is larger than the sum of its proper divisors (175968335).

644302465 is a wasteful number, since it uses less digits than its factorization.

644302465 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15092.

The product of its (nonzero) digits is 69120, while the sum is 34.

The square root of 644302465 is about 25383.1137766823. The cubic root of 644302465 is about 863.7006855191.

The spelling of 644302465 in words is "six hundred forty-four million, three hundred two thousand, four hundred sixty-five".