640680440299 has 2 divisors, whose sum is σ = 640680440300. Its totient is φ = 640680440298.

The previous prime is 640680440293. The next prime is 640680440329. The reversal of 640680440299 is 992044086046.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 640680440299 - 2²¹ = 640678343147 is a prime.

It is not a weakly prime, because it can be changed into another prime (640680440293) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320340220149 + 320340220150.

It is an arithmetic number, because the mean of its divisors is an integer number (320340220150).

Almost surely, 2^640680440299 is an apocalyptic number.

640680440299 is a deficient number, since it is larger than the sum of its proper divisors (1).

640680440299 is an equidigital number, since it uses as much as digits as its factorization.

640680440299 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2985984, while the sum is 52.

The spelling of 640680440299 in words is "six hundred forty billion, six hundred eighty million, four hundred forty thousand, two hundred ninety-nine".