21130223186909 has 2 divisors, whose sum is σ = 21130223186910. Its totient is φ = 21130223186908.

The previous prime is 21130223186867. The next prime is 21130223186929. The reversal of 21130223186909 is 90968132203112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14766727562500 + 6363495624409 = 3842750^2 + 2522597^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21130223186909 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21130223186929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10565111593454 + 10565111593455.

It is an arithmetic number, because the mean of its divisors is an integer number (10565111593455).

Almost surely, 2^{21130223186909} is an apocalyptic number.

It is an amenable number.

21130223186909 is a deficient number, since it is larger than the sum of its proper divisors (1).

21130223186909 is an equidigital number, since it uses as much as digits as its factorization.

21130223186909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 279936, while the sum is 47.

The spelling of 21130223186909 in words is "twenty-one trillion, one hundred thirty billion, two hundred twenty-three million, one hundred eighty-six thousand, nine hundred nine".