20004943684021 has 2 divisors, whose sum is σ = 20004943684022. Its totient is φ = 20004943684020.

The previous prime is 20004943683971. The next prime is 20004943684079. The reversal of 20004943684021 is 12048634940002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19137737608900 + 867206075121 = 4374670^2 + 931239^2 .

It is a cyclic number.

It is not a de Polignac number, because 20004943684021 - 2¹¹ = 20004943681973 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20004943684721) 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 as a sum of consecutive naturals, namely, 10002471842010 + 10002471842011.

It is an arithmetic number, because the mean of its divisors is an integer number (10002471842011).

Almost surely, 2^{20004943684021} is an apocalyptic number.

It is an amenable number.

20004943684021 is a deficient number, since it is larger than the sum of its proper divisors (1).

20004943684021 is an equidigital number, since it uses as much as digits as its factorization.

20004943684021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 331776, while the sum is 43.

The spelling of 20004943684021 in words is "twenty trillion, four billion, nine hundred forty-three million, six hundred eighty-four thousand, twenty-one".