21163171 has 2 divisors, whose sum is σ = 21163172. Its totient is φ = 21163170.

The previous prime is 21163159. The next prime is 21163187. The reversal of 21163171 is 17136112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21163171 - 2⁵ = 21163139 is a prime.

It is not a weakly prime, because it can be changed into another prime (21163141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10581585 + 10581586.

It is an arithmetic number, because the mean of its divisors is an integer number (10581586).

Almost surely, 2^21163171 is an apocalyptic number.

21163171 is a deficient number, since it is larger than the sum of its proper divisors (1).

21163171 is an equidigital number, since it uses as much as digits as its factorization.

21163171 is an evil number, because the sum of its binary digits is even.

The product of its digits is 252, while the sum is 22.

The square root of 21163171 is about 4600.3446610010. The cubic root of 21163171 is about 276.6051405903.

Adding to 21163171 its reverse (17136112), we get a palindrome (38299283).

The spelling of 21163171 in words is "twenty-one million, one hundred sixty-three thousand, one hundred seventy-one".