640318571 has 2 divisors, whose sum is σ = 640318572. Its totient is φ = 640318570.

The previous prime is 640318561. The next prime is 640318573. The reversal of 640318571 is 175813046.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 640318571 - 2²² = 636124267 is a prime.

Together with 640318573, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (640318573) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320159285 + 320159286.

It is an arithmetic number, because the mean of its divisors is an integer number (320159286).

Almost surely, 2^640318571 is an apocalyptic number.

640318571 is a deficient number, since it is larger than the sum of its proper divisors (1).

640318571 is an equidigital number, since it uses as much as digits as its factorization.

640318571 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20160, while the sum is 35.

The square root of 640318571 is about 25304.5168102456. The cubic root of 640318571 is about 861.9168398806.

The spelling of 640318571 in words is "six hundred forty million, three hundred eighteen thousand, five hundred seventy-one".