641665696013 has 4 divisors (see below), whose sum is σ = 642747763548. Its totient is φ = 640583628480.

The previous prime is 641665695949. The next prime is 641665696069. The reversal of 641665696013 is 310696566146.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 358660847689 + 283004848324 = 598883^2 + 531982^2 .

It is a cyclic number.

It is not a de Polignac number, because 641665696013 - 2⁶ = 641665695949 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 (641665696073) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 541032878 + ... + 541034063.

It is an arithmetic number, because the mean of its divisors is an integer number (160686940887).

Almost surely, 2^641665696013 is an apocalyptic number.

It is an amenable number.

641665696013 is a deficient number, since it is larger than the sum of its proper divisors (1082067535).

641665696013 is a wasteful number, since it uses less digits than its factorization.

641665696013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1082067534.

The product of its (nonzero) digits is 4199040, while the sum is 53.

The spelling of 641665696013 in words is "six hundred forty-one billion, six hundred sixty-five million, six hundred ninety-six thousand, thirteen".