640441327 has 2 divisors, whose sum is σ = 640441328. Its totient is φ = 640441326.

The previous prime is 640441301. The next prime is 640441339. The reversal of 640441327 is 723144046.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 640441327 - 2¹¹ = 640439279 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (640441397) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320220663 + 320220664.

It is an arithmetic number, because the mean of its divisors is an integer number (320220664).

Almost surely, 2^640441327 is an apocalyptic number.

640441327 is a deficient number, since it is larger than the sum of its proper divisors (1).

640441327 is an equidigital number, since it uses as much as digits as its factorization.

640441327 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16128, while the sum is 31.

The square root of 640441327 is about 25306.9422688716. The cubic root of 640441327 is about 861.9719159567.

The spelling of 640441327 in words is "six hundred forty million, four hundred forty-one thousand, three hundred twenty-seven".