640545263 has 2 divisors, whose sum is σ = 640545264. Its totient is φ = 640545262.

The previous prime is 640545229. The next prime is 640545277. The reversal of 640545263 is 362545046.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 640545263 - 2²⁰ = 639496687 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (640545203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320272631 + 320272632.

It is an arithmetic number, because the mean of its divisors is an integer number (320272632).

Almost surely, 2^640545263 is an apocalyptic number.

640545263 is a deficient number, since it is larger than the sum of its proper divisors (1).

640545263 is an equidigital number, since it uses as much as digits as its factorization.

640545263 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 86400, while the sum is 35.

The square root of 640545263 is about 25308.9956932313. The cubic root of 640545263 is about 862.0185426932.

The spelling of 640545263 in words is "six hundred forty million, five hundred forty-five thousand, two hundred sixty-three".