21611716701109 has 2 divisors, whose sum is σ = 21611716701110. Its totient is φ = 21611716701108.

The previous prime is 21611716701083. The next prime is 21611716701121. The reversal of 21611716701109 is 90110761711612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11301497532900 + 10310219168209 = 3361770^2 + 3210953^2 .

It is a cyclic number.

It is not a de Polignac number, because 21611716701109 - 2⁹ = 21611716700597 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21611716701139) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10805858350554 + 10805858350555.

It is an arithmetic number, because the mean of its divisors is an integer number (10805858350555).

Almost surely, 2^{21611716701109} is an apocalyptic number.

It is an amenable number.

21611716701109 is a deficient number, since it is larger than the sum of its proper divisors (1).

21611716701109 is an equidigital number, since it uses as much as digits as its factorization.

21611716701109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 31752, while the sum is 43.

The spelling of 21611716701109 in words is "twenty-one trillion, six hundred eleven billion, seven hundred sixteen million, seven hundred one thousand, one hundred nine".