640856177287 has 2 divisors, whose sum is σ = 640856177288. Its totient is φ = 640856177286.

The previous prime is 640856177263. The next prime is 640856177293. The reversal of 640856177287 is 782771658046.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 640856177287 - 2¹⁵ = 640856144519 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (640856177237) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320428088643 + 320428088644.

It is an arithmetic number, because the mean of its divisors is an integer number (320428088644).

Almost surely, 2^640856177287 is an apocalyptic number.

640856177287 is a deficient number, since it is larger than the sum of its proper divisors (1).

640856177287 is an equidigital number, since it uses as much as digits as its factorization.

640856177287 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 31610880, while the sum is 61.

The spelling of 640856177287 in words is "six hundred forty billion, eight hundred fifty-six million, one hundred seventy-seven thousand, two hundred eighty-seven".