21124232209 has 2 divisors, whose sum is σ = 21124232210. Its totient is φ = 21124232208.

The previous prime is 21124232197. The next prime is 21124232231. The reversal of 21124232209 is 90223242112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16912222209 + 4212010000 = 130047^2 + 64900^2 .

It is a cyclic number.

It is not a de Polignac number, because 21124232209 - 2²¹ = 21122135057 is a prime.

It is not a weakly prime, because it can be changed into another prime (21124232299) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10562116104 + 10562116105.

It is an arithmetic number, because the mean of its divisors is an integer number (10562116105).

Almost surely, 2^21124232209 is an apocalyptic number.

It is an amenable number.

21124232209 is a deficient number, since it is larger than the sum of its proper divisors (1).

21124232209 is an equidigital number, since it uses as much as digits as its factorization.

21124232209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3456, while the sum is 28.

The spelling of 21124232209 in words is "twenty-one billion, one hundred twenty-four million, two hundred thirty-two thousand, two hundred nine".