21232123217 has 2 divisors, whose sum is σ = 21232123218. Its totient is φ = 21232123216.

The previous prime is 21232123207. The next prime is 21232123223. The reversal of 21232123217 is 71232123212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19094817856 + 2137305361 = 138184^2 + 46231^2 .

It is a cyclic number.

It is not a de Polignac number, because 21232123217 - 2¹⁶ = 21232057681 is a prime.

It is not a weakly prime, because it can be changed into another prime (21232123207) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10616061608 + 10616061609.

It is an arithmetic number, because the mean of its divisors is an integer number (10616061609).

Almost surely, 2^21232123217 is an apocalyptic number.

It is an amenable number.

21232123217 is a deficient number, since it is larger than the sum of its proper divisors (1).

21232123217 is an equidigital number, since it uses as much as digits as its factorization.

21232123217 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2016, while the sum is 26.

Adding to 21232123217 its reverse (71232123212), we get a palindrome (92464246429).

The spelling of 21232123217 in words is "twenty-one billion, two hundred thirty-two million, one hundred twenty-three thousand, two hundred seventeen".