21221102010221 has 2 divisors, whose sum is σ = 21221102010222. Its totient is φ = 21221102010220.

The previous prime is 21221102010161. The next prime is 21221102010239. The reversal of 21221102010221 is 12201020112212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11554356688900 + 9666745321321 = 3399170^2 + 3109139^2 .

It is a cyclic number.

It is not a de Polignac number, because 21221102010221 - 2³⁴ = 21203922141037 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21221102010221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21221102015221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610551005110 + 10610551005111.

It is an arithmetic number, because the mean of its divisors is an integer number (10610551005111).

Almost surely, 2^{21221102010221} is an apocalyptic number.

It is an amenable number.

21221102010221 is a deficient number, since it is larger than the sum of its proper divisors (1).

21221102010221 is an equidigital number, since it uses as much as digits as its factorization.

21221102010221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 21221102010221 its reverse (12201020112212), we get a palindrome (33422122122433).

The spelling of 21221102010221 in words is "twenty-one trillion, two hundred twenty-one billion, one hundred two million, ten thousand, two hundred twenty-one".