640251144361 has 2 divisors, whose sum is σ = 640251144362. Its totient is φ = 640251144360.

The previous prime is 640251144319. The next prime is 640251144433. The reversal of 640251144361 is 163441152046.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 392321838736 + 247929305625 = 626356^2 + 497925^2 .

It is a cyclic number.

It is not a de Polignac number, because 640251144361 - 2¹⁷ = 640251013289 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 640251144361.

It is not a weakly prime, because it can be changed into another prime (640251144761) 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, 320125572180 + 320125572181.

It is an arithmetic number, because the mean of its divisors is an integer number (320125572181).

Almost surely, 2^640251144361 is an apocalyptic number.

It is an amenable number.

640251144361 is a deficient number, since it is larger than the sum of its proper divisors (1).

640251144361 is an equidigital number, since it uses as much as digits as its factorization.

640251144361 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 69120, while the sum is 37.

The spelling of 640251144361 in words is "six hundred forty billion, two hundred fifty-one million, one hundred forty-four thousand, three hundred sixty-one".