21602426225209 has 2 divisors, whose sum is σ = 21602426225210. Its totient is φ = 21602426225208.

The previous prime is 21602426225207. The next prime is 21602426225351. The reversal of 21602426225209 is 90252262420612.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21462576403984 + 139849821225 = 4632772^2 + 373965^2 .

It is a cyclic number.

It is not a de Polignac number, because 21602426225209 - 2¹ = 21602426225207 is a prime.

Together with 21602426225207, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21602426225201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10801213112604 + 10801213112605.

It is an arithmetic number, because the mean of its divisors is an integer number (10801213112605).

Almost surely, 2^{21602426225209} is an apocalyptic number.

It is an amenable number.

21602426225209 is a deficient number, since it is larger than the sum of its proper divisors (1).

21602426225209 is an equidigital number, since it uses as much as digits as its factorization.

21602426225209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 414720, while the sum is 43.

The spelling of 21602426225209 in words is "twenty-one trillion, six hundred two billion, four hundred twenty-six million, two hundred twenty-five thousand, two hundred nine".