21002262217 has 2 divisors, whose sum is σ = 21002262218. Its totient is φ = 21002262216.

The previous prime is 21002262191. The next prime is 21002262223. The reversal of 21002262217 is 71226220012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20427269776 + 574992441 = 142924^2 + 23979^2 .

It is a cyclic number.

It is not a de Polignac number, because 21002262217 - 2¹⁵ = 21002229449 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21002262191 and 21002262200.

It is not a weakly prime, because it can be changed into another prime (21002262227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10501131108 + 10501131109.

It is an arithmetic number, because the mean of its divisors is an integer number (10501131109).

Almost surely, 2^21002262217 is an apocalyptic number.

It is an amenable number.

21002262217 is a deficient number, since it is larger than the sum of its proper divisors (1).

21002262217 is an equidigital number, since it uses as much as digits as its factorization.

21002262217 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1344, while the sum is 25.

Adding to 21002262217 its reverse (71226220012), we get a palindrome (92228482229).

The spelling of 21002262217 in words is "twenty-one billion, two million, two hundred sixty-two thousand, two hundred seventeen".