21000211202171 has 2 divisors, whose sum is σ = 21000211202172. Its totient is φ = 21000211202170.

The previous prime is 21000211202063. The next prime is 21000211202183. The reversal of 21000211202171 is 17120211200012.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21000211202171 - 2¹⁰ = 21000211201147 is a prime.

It is a super-2 number, since 2×21000211202171² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21000211202771) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500105601085 + 10500105601086.

It is an arithmetic number, because the mean of its divisors is an integer number (10500105601086).

Almost surely, 2^{21000211202171} is an apocalyptic number.

21000211202171 is a deficient number, since it is larger than the sum of its proper divisors (1).

21000211202171 is an equidigital number, since it uses as much as digits as its factorization.

21000211202171 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 112, while the sum is 20.

Adding to 21000211202171 its reverse (17120211200012), we get a palindrome (38120422402183).

The spelling of 21000211202171 in words is "twenty-one trillion, two hundred eleven million, two hundred two thousand, one hundred seventy-one".