640340425537 has 2 divisors, whose sum is σ = 640340425538. Its totient is φ = 640340425536.

The previous prime is 640340425511. The next prime is 640340425547. The reversal of 640340425537 is 735524043046.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 368575266816 + 271765158721 = 607104^2 + 521311^2 .

It is a cyclic number.

It is not a de Polignac number, because 640340425537 - 2⁷ = 640340425409 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 640340425493 and 640340425502.

It is not a weakly prime, because it can be changed into another prime (640340425507) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320170212768 + 320170212769.

It is an arithmetic number, because the mean of its divisors is an integer number (320170212769).

Almost surely, 2^640340425537 is an apocalyptic number.

It is an amenable number.

640340425537 is a deficient number, since it is larger than the sum of its proper divisors (1).

640340425537 is an equidigital number, since it uses as much as digits as its factorization.

640340425537 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1209600, while the sum is 43.

The spelling of 640340425537 in words is "six hundred forty billion, three hundred forty million, four hundred twenty-five thousand, five hundred thirty-seven".