20003506736221 has 2 divisors, whose sum is σ = 20003506736222. Its totient is φ = 20003506736220.

The previous prime is 20003506736219. The next prime is 20003506736233. The reversal of 20003506736221 is 12263760530002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16364897076025 + 3638609660196 = 4045355^2 + 1907514^2 .

It is a cyclic number.

It is not a de Polignac number, because 20003506736221 - 2¹ = 20003506736219 is a prime.

Together with 20003506736219, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20003506736201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10001753368110 + 10001753368111.

It is an arithmetic number, because the mean of its divisors is an integer number (10001753368111).

Almost surely, 2^{20003506736221} is an apocalyptic number.

It is an amenable number.

20003506736221 is a deficient number, since it is larger than the sum of its proper divisors (1).

20003506736221 is an equidigital number, since it uses as much as digits as its factorization.

20003506736221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 90720, while the sum is 37.

The spelling of 20003506736221 in words is "twenty trillion, three billion, five hundred six million, seven hundred thirty-six thousand, two hundred twenty-one".