645738705 has 12 divisors (see below), whose sum is σ = 1119280500. Its totient is φ = 344393952.

The previous prime is 645738673. The next prime is 645738707. The reversal of 645738705 is 507837546.

645738705 is a `hidden beast` number, since 6 + 4 + 573 + 8 + 70 + 5 = 666.

645738705 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 486070209 + 159668496 = 22047^2 + 12636^2 .

It is not a de Polignac number, because 645738705 - 2⁵ = 645738673 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45), and also a Moran number because the ratio is a prime number: 14349749 = 645738705 / (6 + 4 + 5 + 7 + 3 + 8 + 7 + 0 + 5).

It is not an unprimeable number, because it can be changed into a prime (645738707) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7174830 + ... + 7174919.

It is an arithmetic number, because the mean of its divisors is an integer number (93273375).

Almost surely, 2^645738705 is an apocalyptic number.

It is an amenable number.

645738705 is a deficient number, since it is larger than the sum of its proper divisors (473541795).

645738705 is a wasteful number, since it uses less digits than its factorization.

645738705 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14349760 (or 14349757 counting only the distinct ones).

The product of its (nonzero) digits is 705600, while the sum is 45.

The square root of 645738705 is about 25411.3892772513. The cubic root of 645738705 is about 864.3419789821.

The spelling of 645738705 in words is "six hundred forty-five million, seven hundred thirty-eight thousand, seven hundred five".