640513567 has 2 divisors, whose sum is σ = 640513568. Its totient is φ = 640513566.

The previous prime is 640513543. The next prime is 640513571. The reversal of 640513567 is 765315046.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-640513567 is a prime.

It is a super-2 number, since 2×640513567² = 820515259022126978, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (640513067) 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 as a sum of consecutive naturals, namely, 320256783 + 320256784.

It is an arithmetic number, because the mean of its divisors is an integer number (320256784).

Almost surely, 2^640513567 is an apocalyptic number.

640513567 is a deficient number, since it is larger than the sum of its proper divisors (1).

640513567 is an equidigital number, since it uses as much as digits as its factorization.

640513567 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 75600, while the sum is 37.

The square root of 640513567 is about 25308.3695049681. The cubic root of 640513567 is about 862.0043240829.

The spelling of 640513567 in words is "six hundred forty million, five hundred thirteen thousand, five hundred sixty-seven".