640027 has 2 divisors, whose sum is σ = 640028. Its totient is φ = 640026.

The previous prime is 640019. The next prime is 640039. The reversal of 640027 is 720046.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 640027 - 2³ = 640019 is a prime.

It is a nialpdrome in base 15.

It is a junction number, because it is equal to n+sod(n) for n = 639986 and 640013.

It is not a weakly prime, because it can be changed into another prime (640007) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320013 + 320014.

It is an arithmetic number, because the mean of its divisors is an integer number (320014).

2⁶⁴⁰⁰²⁷ is an apocalyptic number.

640027 is a deficient number, since it is larger than the sum of its proper divisors (1).

640027 is an equidigital number, since it uses as much as digits as its factorization.

640027 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 336, while the sum is 19.

The square root of 640027 is about 800.0168748220. The cubic root of 640027 is about 86.1785994537.

Adding to 640027 its sum of digits (19), we get a palindrome (640046).

It can be divided in two parts, 64002 and 7, that added together give a square (64009 = 253²).

The spelling of 640027 in words is "six hundred forty thousand, twenty-seven".