21523210529 has 2 divisors, whose sum is σ = 21523210530. Its totient is φ = 21523210528.

The previous prime is 21523210453. The next prime is 21523210531. The reversal of 21523210529 is 92501232512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21510622225 + 12588304 = 146665^2 + 3548^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21523210529 is a prime.

Together with 21523210531, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 21523210495 and 21523210504.

It is not a weakly prime, because it can be changed into another prime (21523210129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10761605264 + 10761605265.

It is an arithmetic number, because the mean of its divisors is an integer number (10761605265).

Almost surely, 2^21523210529 is an apocalyptic number.

It is an amenable number.

21523210529 is a deficient number, since it is larger than the sum of its proper divisors (1).

21523210529 is an equidigital number, since it uses as much as digits as its factorization.

21523210529 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10800, while the sum is 32.

The spelling of 21523210529 in words is "twenty-one billion, five hundred twenty-three million, two hundred ten thousand, five hundred twenty-nine".