640065563 has 2 divisors, whose sum is σ = 640065564. Its totient is φ = 640065562.

The previous prime is 640065511. The next prime is 640065581. The reversal of 640065563 is 365560046.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 640065563 - 2⁶ = 640065499 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (640065593) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320032781 + 320032782.

It is an arithmetic number, because the mean of its divisors is an integer number (320032782).

Almost surely, 2^640065563 is an apocalyptic number.

640065563 is a deficient number, since it is larger than the sum of its proper divisors (1).

640065563 is an equidigital number, since it uses as much as digits as its factorization.

640065563 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 64800, while the sum is 35.

The square root of 640065563 is about 25299.5170507265. The cubic root of 640065563 is about 861.8033023416.

The spelling of 640065563 in words is "six hundred forty million, sixty-five thousand, five hundred sixty-three".