643202812841 has 4 divisors (see below), whose sum is σ = 643216762884. Its totient is φ = 643188862800.

The previous prime is 643202812729. The next prime is 643202812853. The reversal of 643202812841 is 148218202346.

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 543080563600 + 100122249241 = 736940^2 + 316421^2 .

It is a cyclic number.

It is not a de Polignac number, because 643202812841 - 2²² = 643198618537 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (643202811841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6905630 + ... + 6998151.

It is an arithmetic number, because the mean of its divisors is an integer number (160804190721).

Almost surely, 2^643202812841 is an apocalyptic number.

It is an amenable number.

643202812841 is a deficient number, since it is larger than the sum of its proper divisors (13950043).

643202812841 is a wasteful number, since it uses less digits than its factorization.

643202812841 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13950042.

The product of its (nonzero) digits is 147456, while the sum is 41.

The spelling of 643202812841 in words is "six hundred forty-three billion, two hundred two million, eight hundred twelve thousand, eight hundred forty-one".