21230171 has 2 divisors, whose sum is σ = 21230172. Its totient is φ = 21230170.

The previous prime is 21230159. The next prime is 21230177. The reversal of 21230171 is 17103212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21230171 - 2¹⁰ = 21229147 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21230177) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10615085 + 10615086.

It is an arithmetic number, because the mean of its divisors is an integer number (10615086).

Almost surely, 2^21230171 is an apocalyptic number.

21230171 is a deficient number, since it is larger than the sum of its proper divisors (1).

21230171 is an equidigital number, since it uses as much as digits as its factorization.

21230171 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 84, while the sum is 17.

The square root of 21230171 is about 4607.6209696545. The cubic root of 21230171 is about 276.8967323922.

Adding to 21230171 its reverse (17103212), we get a palindrome (38333383).

The spelling of 21230171 in words is "twenty-one million, two hundred thirty thousand, one hundred seventy-one".