21214204217 has 2 divisors, whose sum is σ = 21214204218. Its totient is φ = 21214204216.

The previous prime is 21214204213. The next prime is 21214204337. The reversal of 21214204217 is 71240241212.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19987173376 + 1227030841 = 141376^2 + 35029^2 .

It is a cyclic number.

It is not a de Polignac number, because 21214204217 - 2² = 21214204213 is a prime.

It is not a weakly prime, because it can be changed into another prime (21214204213) 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, 10607102108 + 10607102109.

It is an arithmetic number, because the mean of its divisors is an integer number (10607102109).

Almost surely, 2^21214204217 is an apocalyptic number.

It is an amenable number.

21214204217 is a deficient number, since it is larger than the sum of its proper divisors (1).

21214204217 is an equidigital number, since it uses as much as digits as its factorization.

21214204217 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1792, while the sum is 26.

Adding to 21214204217 its reverse (71240241212), we get a palindrome (92454445429).

The spelling of 21214204217 in words is "twenty-one billion, two hundred fourteen million, two hundred four thousand, two hundred seventeen".