640409730019 has 2 divisors, whose sum is σ = 640409730020. Its totient is φ = 640409730018.

The previous prime is 640409730017. The next prime is 640409730109. The reversal of 640409730019 is 910037904046.

Together with next prime (640409730109) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 640409730019 - 2¹ = 640409730017 is a prime.

It is a super-2 number, since 2×640409730019² (a number of 24 digits) contains 22 as substring.

Together with 640409730017, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (640409730011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320204865009 + 320204865010.

It is an arithmetic number, because the mean of its divisors is an integer number (320204865010).

Almost surely, 2^640409730019 is an apocalyptic number.

640409730019 is a deficient number, since it is larger than the sum of its proper divisors (1).

640409730019 is an equidigital number, since it uses as much as digits as its factorization.

640409730019 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 163296, while the sum is 43.

The spelling of 640409730019 in words is "six hundred forty billion, four hundred nine million, seven hundred thirty thousand, nineteen".