640642113325 has 6 divisors (see below), whose sum is σ = 794396220554. Its totient is φ = 512513690640.

The previous prime is 640642113323. The next prime is 640642113337. The reversal of 640642113325 is 523311246046.

It can be written as a sum of positive squares in 3 ways, for example, as 16183401796 + 624458711529 = 127214^2 + 790227^2 .

It is not a de Polignac number, because 640642113325 - 2¹ = 640642113323 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640642113323) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 12812842242 + ... + 12812842291.

Almost surely, 2^640642113325 is an apocalyptic number.

It is an amenable number.

640642113325 is a deficient number, since it is larger than the sum of its proper divisors (153754107229).

640642113325 is a wasteful number, since it uses less digits than its factorization.

640642113325 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25625684543 (or 25625684538 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 37.

The spelling of 640642113325 in words is "six hundred forty billion, six hundred forty-two million, one hundred thirteen thousand, three hundred twenty-five".