216685697744393 has 2 divisors, whose sum is σ = 216685697744394. Its totient is φ = 216685697744392.

The previous prime is 216685697744311. The next prime is 216685697744471. The reversal of 216685697744393 is 393447796586612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 210538010565184 + 6147687179209 = 14509928^2 + 2479453^2 .

It is a cyclic number.

It is not a de Polignac number, because 216685697744393 - 2¹⁴ = 216685697728009 is a prime.

It is not a weakly prime, because it can be changed into another prime (216685697741393) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108342848872196 + 108342848872197.

It is an arithmetic number, because the mean of its divisors is an integer number (108342848872197).

Almost surely, 2^{216685697744393} is an apocalyptic number.

It is an amenable number.

216685697744393 is a deficient number, since it is larger than the sum of its proper divisors (1).

216685697744393 is an equidigital number, since it uses as much as digits as its factorization.

216685697744393 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9876142080, while the sum is 80.

The spelling of 216685697744393 in words is "two hundred sixteen trillion, six hundred eighty-five billion, six hundred ninety-seven million, seven hundred forty-four thousand, three hundred ninety-three".