21323202217 has 2 divisors, whose sum is σ = 21323202218. Its totient is φ = 21323202216.

The previous prime is 21323202211. The next prime is 21323202239. The reversal of 21323202217 is 71220232312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19461366016 + 1861836201 = 139504^2 + 43149^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21323202217 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21323202191 and 21323202200.

It is not a weakly prime, because it can be changed into another prime (21323202211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10661601108 + 10661601109.

It is an arithmetic number, because the mean of its divisors is an integer number (10661601109).

Almost surely, 2^21323202217 is an apocalyptic number.

It is an amenable number.

21323202217 is a deficient number, since it is larger than the sum of its proper divisors (1).

21323202217 is an equidigital number, since it uses as much as digits as its factorization.

21323202217 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2016, while the sum is 25.

Adding to 21323202217 its reverse (71220232312), we get a palindrome (92543434529).

The spelling of 21323202217 in words is "twenty-one billion, three hundred twenty-three million, two hundred two thousand, two hundred seventeen".