21201222211171 has 2 divisors, whose sum is σ = 21201222211172. Its totient is φ = 21201222211170.

The previous prime is 21201222211121. The next prime is 21201222211193. The reversal of 21201222211171 is 17111222210212.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21201222211171 - 2¹⁵ = 21201222178403 is a prime.

It is a super-3 number, since 3×21201222211171³ (a number of 41 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (21201222211121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10600611105585 + 10600611105586.

It is an arithmetic number, because the mean of its divisors is an integer number (10600611105586).

Almost surely, 2^{21201222211171} is an apocalyptic number.

21201222211171 is a deficient number, since it is larger than the sum of its proper divisors (1).

21201222211171 is an equidigital number, since it uses as much as digits as its factorization.

21201222211171 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 448, while the sum is 25.

Adding to 21201222211171 its reverse (17111222210212), we get a palindrome (38312444421383).

The spelling of 21201222211171 in words is "twenty-one trillion, two hundred one billion, two hundred twenty-two million, two hundred eleven thousand, one hundred seventy-one".