21112242209 has 2 divisors, whose sum is σ = 21112242210. Its totient is φ = 21112242208.

The previous prime is 21112242199. The next prime is 21112242241. The reversal of 21112242209 is 90224221112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15693073984 + 5419168225 = 125272^2 + 73615^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21112242209 is a prime.

It is not a weakly prime, because it can be changed into another prime (21112242289) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10556121104 + 10556121105.

It is an arithmetic number, because the mean of its divisors is an integer number (10556121105).

Almost surely, 2^21112242209 is an apocalyptic number.

It is an amenable number.

21112242209 is a deficient number, since it is larger than the sum of its proper divisors (1).

21112242209 is an equidigital number, since it uses as much as digits as its factorization.

21112242209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1152, while the sum is 26.

The spelling of 21112242209 in words is "twenty-one billion, one hundred twelve million, two hundred forty-two thousand, two hundred nine".