20835491668489 has 2 divisors, whose sum is σ = 20835491668490. Its totient is φ = 20835491668488.

The previous prime is 20835491668441. The next prime is 20835491668513. The reversal of 20835491668489 is 98486619453802.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20601912778489 + 233578890000 = 4538933^2 + 483300^2 .

It is a cyclic number.

It is not a de Polignac number, because 20835491668489 - 2²³ = 20835483279881 is a prime.

It is not a weakly prime, because it can be changed into another prime (20835491666489) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10417745834244 + 10417745834245.

It is an arithmetic number, because the mean of its divisors is an integer number (10417745834245).

Almost surely, 2^{20835491668489} is an apocalyptic number.

It is an amenable number.

20835491668489 is a deficient number, since it is larger than the sum of its proper divisors (1).

20835491668489 is an equidigital number, since it uses as much as digits as its factorization.

20835491668489 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 716636160, while the sum is 73.

The spelling of 20835491668489 in words is "twenty trillion, eight hundred thirty-five billion, four hundred ninety-one million, six hundred sixty-eight thousand, four hundred eighty-nine".