211021209999689 has 2 divisors, whose sum is σ = 211021209999690. Its totient is φ = 211021209999688.

The previous prime is 211021209999647. The next prime is 211021209999713. The reversal of 211021209999689 is 986999902120112.

211021209999689 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., 177428660455225 + 33592549544464 = 13320235^2 + 5795908^2 .

It is a cyclic number.

It is not a de Polignac number, because 211021209999689 - 2¹² = 211021209995593 is a prime.

It is not a weakly prime, because it can be changed into another prime (211021209999619) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105510604999844 + 105510604999845.

It is an arithmetic number, because the mean of its divisors is an integer number (105510604999845).

Almost surely, 2^{211021209999689} is an apocalyptic number.

It is an amenable number.

211021209999689 is a deficient number, since it is larger than the sum of its proper divisors (1).

211021209999689 is an equidigital number, since it uses as much as digits as its factorization.

211021209999689 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 22674816, while the sum is 68.

The spelling of 211021209999689 in words is "two hundred eleven trillion, twenty-one billion, two hundred nine million, nine hundred ninety-nine thousand, six hundred eighty-nine".