641781980609 has 24 divisors (see below), whose sum is σ = 814619786400. Its totient is φ = 499974578880.

The previous prime is 641781980597. The next prime is 641781980629. The reversal of 641781980609 is 906089187146.

It is not a de Polignac number, because 641781980609 - 2¹² = 641781976513 is a prime.

It is a super-2 number, since 2×641781980609² (a number of 24 digits) contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (641781980629) 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 23 ways as a sum of consecutive naturals, for example, 2241422 + ... + 2511480.

It is an arithmetic number, because the mean of its divisors is an integer number (33942491100).

Almost surely, 2^641781980609 is an apocalyptic number.

It is an amenable number.

641781980609 is a deficient number, since it is larger than the sum of its proper divisors (172837805791).

641781980609 is a wasteful number, since it uses less digits than its factorization.

641781980609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 274493 (or 274486 counting only the distinct ones).

The product of its (nonzero) digits is 5225472, while the sum is 59.

The spelling of 641781980609 in words is "six hundred forty-one billion, seven hundred eighty-one million, nine hundred eighty thousand, six hundred nine".