640436620277 has 2 divisors, whose sum is σ = 640436620278. Its totient is φ = 640436620276.

The previous prime is 640436620259. The next prime is 640436620349. The reversal of 640436620277 is 772026634046.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 607088747281 + 33347872996 = 779159^2 + 182614^2 .

It is a cyclic number.

It is not a de Polignac number, because 640436620277 - 2²² = 640432425973 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (640436620217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320218310138 + 320218310139.

It is an arithmetic number, because the mean of its divisors is an integer number (320218310139).

Almost surely, 2^640436620277 is an apocalyptic number.

It is an amenable number.

640436620277 is a deficient number, since it is larger than the sum of its proper divisors (1).

640436620277 is an equidigital number, since it uses as much as digits as its factorization.

640436620277 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2032128, while the sum is 47.

The spelling of 640436620277 in words is "six hundred forty billion, four hundred thirty-six million, six hundred twenty thousand, two hundred seventy-seven".