21151171 has 2 divisors, whose sum is σ = 21151172. Its totient is φ = 21151170.

The previous prime is 21151159. The next prime is 21151183. The reversal of 21151171 is 17115112.

It is a balanced prime because it is at equal distance from previous prime (21151159) and next prime (21151183).

It is a cyclic number.

It is not a de Polignac number, because 21151171 - 2⁹ = 21150659 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21151271) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10575585 + 10575586.

It is an arithmetic number, because the mean of its divisors is an integer number (10575586).

Almost surely, 2^21151171 is an apocalyptic number.

21151171 is a deficient number, since it is larger than the sum of its proper divisors (1).

21151171 is an equidigital number, since it uses as much as digits as its factorization.

21151171 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 70, while the sum is 19.

The square root of 21151171 is about 4599.0402259602. The cubic root of 21151171 is about 276.5528502341.

Adding to 21151171 its reverse (17115112), we get a palindrome (38266283).

The spelling of 21151171 in words is "twenty-one million, one hundred fifty-one thousand, one hundred seventy-one".