20621442536417 has 2 divisors, whose sum is σ = 20621442536418. Its totient is φ = 20621442536416.

The previous prime is 20621442536407. The next prime is 20621442536441. The reversal of 20621442536417 is 71463524412602.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13321886807056 + 7299555729361 = 3649916^2 + 2701769^2 .

It is a cyclic number.

It is not a de Polignac number, because 20621442536417 - 2¹⁴ = 20621442520033 is a prime.

It is not a weakly prime, because it can be changed into another prime (20621442536407) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10310721268208 + 10310721268209.

It is an arithmetic number, because the mean of its divisors is an integer number (10310721268209).

Almost surely, 2^{20621442536417} is an apocalyptic number.

It is an amenable number.

20621442536417 is a deficient number, since it is larger than the sum of its proper divisors (1).

20621442536417 is an equidigital number, since it uses as much as digits as its factorization.

20621442536417 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1935360, while the sum is 47.

The spelling of 20621442536417 in words is "twenty trillion, six hundred twenty-one billion, four hundred forty-two million, five hundred thirty-six thousand, four hundred seventeen".