21132213209 has 2 divisors, whose sum is σ = 21132213210. Its totient is φ = 21132213208.

The previous prime is 21132213199. The next prime is 21132213247. The reversal of 21132213209 is 90231223112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15079840000 + 6052373209 = 122800^2 + 77797^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21132213209 is a prime.

It is a super-2 number, since 2×21132213209² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21132213299) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10566106604 + 10566106605.

It is an arithmetic number, because the mean of its divisors is an integer number (10566106605).

Almost surely, 2^21132213209 is an apocalyptic number.

It is an amenable number.

21132213209 is a deficient number, since it is larger than the sum of its proper divisors (1).

21132213209 is an equidigital number, since it uses as much as digits as its factorization.

21132213209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1296, while the sum is 26.

The spelling of 21132213209 in words is "twenty-one billion, one hundred thirty-two million, two hundred thirteen thousand, two hundred nine".