21140224040209 has 2 divisors, whose sum is σ = 21140224040210. Its totient is φ = 21140224040208.

The previous prime is 21140224040207. The next prime is 21140224040239. The reversal of 21140224040209 is 90204042204112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13922151937600 + 7218072102609 = 3731240^2 + 2686647^2 .

It is a cyclic number.

It is not a de Polignac number, because 21140224040209 - 2¹ = 21140224040207 is a prime.

Together with 21140224040207, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21140224040207) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10570112020104 + 10570112020105.

It is an arithmetic number, because the mean of its divisors is an integer number (10570112020105).

Almost surely, 2^{21140224040209} is an apocalyptic number.

It is an amenable number.

21140224040209 is a deficient number, since it is larger than the sum of its proper divisors (1).

21140224040209 is an equidigital number, since it uses as much as digits as its factorization.

21140224040209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9216, while the sum is 31.

The spelling of 21140224040209 in words is "twenty-one trillion, one hundred forty billion, two hundred twenty-four million, forty thousand, two hundred nine".