640522247 has 2 divisors, whose sum is σ = 640522248. Its totient is φ = 640522246.

The previous prime is 640522237. The next prime is 640522291. The reversal of 640522247 is 742225046.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 640522247 - 2¹⁶ = 640456711 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (640522237) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320261123 + 320261124.

It is an arithmetic number, because the mean of its divisors is an integer number (320261124).

Almost surely, 2^640522247 is an apocalyptic number.

640522247 is a deficient number, since it is larger than the sum of its proper divisors (1).

640522247 is an equidigital number, since it uses as much as digits as its factorization.

640522247 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 26880, while the sum is 32.

The square root of 640522247 is about 25308.5409891602. The cubic root of 640522247 is about 862.0082179186.

The spelling of 640522247 in words is "six hundred forty million, five hundred twenty-two thousand, two hundred forty-seven".