20004357543421 has 2 divisors, whose sum is σ = 20004357543422. Its totient is φ = 20004357543420.

The previous prime is 20004357543413. The next prime is 20004357543437. The reversal of 20004357543421 is 12434575340002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19709035944196 + 295321599225 = 4439486^2 + 543435^2 .

It is a cyclic number.

It is not a de Polignac number, because 20004357543421 - 2³ = 20004357543413 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20004357540421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10002178771710 + 10002178771711.

It is an arithmetic number, because the mean of its divisors is an integer number (10002178771711).

Almost surely, 2^{20004357543421} is an apocalyptic number.

It is an amenable number.

20004357543421 is a deficient number, since it is larger than the sum of its proper divisors (1).

20004357543421 is an equidigital number, since it uses as much as digits as its factorization.

20004357543421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 403200, while the sum is 40.

The spelling of 20004357543421 in words is "twenty trillion, four billion, three hundred fifty-seven million, five hundred forty-three thousand, four hundred twenty-one".