645446563 has 4 divisors (see below), whose sum is σ = 650373768. Its totient is φ = 640519360.

The previous prime is 645446521. The next prime is 645446569. The reversal of 645446563 is 365644546.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 365644546 = 2 ⋅182822273.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-645446563 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645446569) 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 3 ways as a sum of consecutive naturals, for example, 2463406 + ... + 2463667.

It is an arithmetic number, because the mean of its divisors is an integer number (162593442).

Almost surely, 2^645446563 is an apocalyptic number.

645446563 is a deficient number, since it is larger than the sum of its proper divisors (4927205).

645446563 is a wasteful number, since it uses less digits than its factorization.

645446563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4927204.

The product of its digits is 1036800, while the sum is 43.

The square root of 645446563 is about 25405.6403776799. The cubic root of 645446563 is about 864.2116121727.

The spelling of 645446563 in words is "six hundred forty-five million, four hundred forty-six thousand, five hundred sixty-three".