643309629573889 has 4 divisors (see below), whose sum is σ = 644187268905556. Its totient is φ = 642431990242224.

The previous prime is 643309629573839. The next prime is 643309629573907. The reversal of 643309629573889 is 988375926903346.

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 609295166049025 + 34014463524864 = 24683905^2 + 5832192^2 .

It is a cyclic number.

It is not a de Polignac number, because 643309629573889 - 2¹¹ = 643309629571841 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (643309629573839) 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, 438819664734 + ... + 438819666199.

It is an arithmetic number, because the mean of its divisors is an integer number (161046817226389).

Almost surely, 2^{643309629573889} is an apocalyptic number.

It is an amenable number.

643309629573889 is a deficient number, since it is larger than the sum of its proper divisors (877639331667).

643309629573889 is an equidigital number, since it uses as much as digits as its factorization.

643309629573889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 877639331666.

The product of its (nonzero) digits is 12697896960, while the sum is 82.

The spelling of 643309629573889 in words is "six hundred forty-three trillion, three hundred nine billion, six hundred twenty-nine million, five hundred seventy-three thousand, eight hundred eighty-nine".