21332009 has 2 divisors, whose sum is σ = 21332010. Its totient is φ = 21332008.

The previous prime is 21331993. The next prime is 21332029. The reversal of 21332009 is 90023312.

It is an a-pointer prime, because the next prime (21332029) can be obtained adding 21332009 to its sum of digits (20).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21187609 + 144400 = 4603^2 + 380^2 .

It is a cyclic number.

It is not a de Polignac number, because 21332009 - 2⁴ = 21331993 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21332029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10666004 + 10666005.

It is an arithmetic number, because the mean of its divisors is an integer number (10666005).

Almost surely, 2^21332009 is an apocalyptic number.

It is an amenable number.

21332009 is a deficient number, since it is larger than the sum of its proper divisors (1).

21332009 is an equidigital number, since it uses as much as digits as its factorization.

21332009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 324, while the sum is 20.

The square root of 21332009 is about 4618.6587880033. The cubic root of 21332009 is about 277.3387706124.

The spelling of 21332009 in words is "twenty-one million, three hundred thirty-two thousand, nine".