20659890889549 has 2 divisors, whose sum is σ = 20659890889550. Its totient is φ = 20659890889548.

The previous prime is 20659890889537. The next prime is 20659890889567. The reversal of 20659890889549 is 94598809895602.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12281471187049 + 8378419702500 = 3504493^2 + 2894550^2 .

It is a cyclic number.

It is not a de Polignac number, because 20659890889549 - 2¹¹ = 20659890887501 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20659890880549) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10329945444774 + 10329945444775.

It is an arithmetic number, because the mean of its divisors is an integer number (10329945444775).

Almost surely, 2^{20659890889549} is an apocalyptic number.

It is an amenable number.

20659890889549 is a deficient number, since it is larger than the sum of its proper divisors (1).

20659890889549 is an equidigital number, since it uses as much as digits as its factorization.

20659890889549 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4031078400, while the sum is 82.

The spelling of 20659890889549 in words is "twenty trillion, six hundred fifty-nine billion, eight hundred ninety million, eight hundred eighty-nine thousand, five hundred forty-nine".