640680308101 has 2 divisors, whose sum is σ = 640680308102. Its totient is φ = 640680308100.

The previous prime is 640680308029. The next prime is 640680308141. The reversal of 640680308101 is 101803086046.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 639464112225 + 1216195876 = 799665^2 + 34874^2 .

It is a cyclic number.

It is not a de Polignac number, because 640680308101 - 2¹¹ = 640680306053 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (640680308141) 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, 320340154050 + 320340154051.

It is an arithmetic number, because the mean of its divisors is an integer number (320340154051).

Almost surely, 2^640680308101 is an apocalyptic number.

It is an amenable number.

640680308101 is a deficient number, since it is larger than the sum of its proper divisors (1).

640680308101 is an equidigital number, since it uses as much as digits as its factorization.

640680308101 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 27648, while the sum is 37.

The spelling of 640680308101 in words is "six hundred forty billion, six hundred eighty million, three hundred eight thousand, one hundred one".