640680308143 has 2 divisors, whose sum is σ = 640680308144. Its totient is φ = 640680308142.

The previous prime is 640680308141. The next prime is 640680308173. The reversal of 640680308143 is 341803086046.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 640680308143 - 2¹ = 640680308141 is a prime.

Together with 640680308141, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 640680308143.

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 polite number, since it can be written as a sum of consecutive naturals, namely, 320340154071 + 320340154072.

It is an arithmetic number, because the mean of its divisors is an integer number (320340154072).

Almost surely, 2^640680308143 is an apocalyptic number.

640680308143 is a deficient number, since it is larger than the sum of its proper divisors (1).

640680308143 is an equidigital number, since it uses as much as digits as its factorization.

640680308143 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 331776, while the sum is 43.

The spelling of 640680308143 in words is "six hundred forty billion, six hundred eighty million, three hundred eight thousand, one hundred forty-three".