16661172205393 has 2 divisors, whose sum is σ = 16661172205394. Its totient is φ = 16661172205392.

The previous prime is 16661172205357. The next prime is 16661172205417. The reversal of 16661172205393 is 39350227116661.

16661172205393 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16547257180224 + 113915025169 = 4067832^2 + 337513^2 .

It is a cyclic number.

It is not a de Polignac number, because 16661172205393 - 2¹⁷ = 16661172074321 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 16661172205393.

It is not a weakly prime, because it can be changed into another prime (16661172205313) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8330586102696 + 8330586102697.

It is an arithmetic number, because the mean of its divisors is an integer number (8330586102697).

Almost surely, 2^{16661172205393} is an apocalyptic number.

It is an amenable number.

16661172205393 is a deficient number, since it is larger than the sum of its proper divisors (1).

16661172205393 is an equidigital number, since it uses as much as digits as its factorization.

16661172205393 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2449440, while the sum is 52.

The spelling of 16661172205393 in words is "sixteen trillion, six hundred sixty-one billion, one hundred seventy-two million, two hundred five thousand, three hundred ninety-three".