16339720687321 has 2 divisors, whose sum is σ = 16339720687322. Its totient is φ = 16339720687320.

The previous prime is 16339720687291. The next prime is 16339720687337. The reversal of 16339720687321 is 12378602793361.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10846720686096 + 5493000001225 = 3293436^2 + 2343715^2 .

It is a cyclic number.

It is not a de Polignac number, because 16339720687321 - 2¹⁹ = 16339720163033 is a prime.

It is not a weakly prime, because it can be changed into another prime (16339720687391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8169860343660 + 8169860343661.

It is an arithmetic number, because the mean of its divisors is an integer number (8169860343661).

Almost surely, 2^{16339720687321} is an apocalyptic number.

It is an amenable number.

16339720687321 is a deficient number, since it is larger than the sum of its proper divisors (1).

16339720687321 is an equidigital number, since it uses as much as digits as its factorization.

16339720687321 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13716864, while the sum is 58.

The spelling of 16339720687321 in words is "sixteen trillion, three hundred thirty-nine billion, seven hundred twenty million, six hundred eighty-seven thousand, three hundred twenty-one".