641243709389 has 8 divisors (see below), whose sum is σ = 653750817912. Its totient is φ = 628751718400.

The previous prime is 641243709361. The next prime is 641243709391. The reversal of 641243709389 is 983907342146.

It can be written as a sum of positive squares in 4 ways, for example, as 489883806889 + 151359902500 = 699917^2 + 389050^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 641243709389 - 2³⁶ = 572524232653 is a prime.

It is a super-2 number, since 2×641243709389² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641243709889) 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 7 ways as a sum of consecutive naturals, for example, 3693704 + ... + 3863409.

It is an arithmetic number, because the mean of its divisors is an integer number (81718852239).

Almost surely, 2^641243709389 is an apocalyptic number.

It is an amenable number.

641243709389 is a deficient number, since it is larger than the sum of its proper divisors (12507108523).

641243709389 is a wasteful number, since it uses less digits than its factorization.

641243709389 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7558767.

The product of its (nonzero) digits is 7838208, while the sum is 56.

The spelling of 641243709389 in words is "six hundred forty-one billion, two hundred forty-three million, seven hundred nine thousand, three hundred eighty-nine".