21203327209 has 2 divisors, whose sum is σ = 21203327210. Its totient is φ = 21203327208.

The previous prime is 21203327203. The next prime is 21203327221. The reversal of 21203327209 is 90272330212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17225250025 + 3978077184 = 131245^2 + 63072^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21203327209 is a prime.

It is not a weakly prime, because it can be changed into another prime (21203327203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10601663604 + 10601663605.

It is an arithmetic number, because the mean of its divisors is an integer number (10601663605).

Almost surely, 2^21203327209 is an apocalyptic number.

It is an amenable number.

21203327209 is a deficient number, since it is larger than the sum of its proper divisors (1).

21203327209 is an equidigital number, since it uses as much as digits as its factorization.

21203327209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9072, while the sum is 31.

The spelling of 21203327209 in words is "twenty-one billion, two hundred three million, three hundred twenty-seven thousand, two hundred nine".