20647171 has 2 divisors, whose sum is σ = 20647172. Its totient is φ = 20647170.

The previous prime is 20647141. The next prime is 20647177. The reversal of 20647171 is 17174602.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20647171 - 2⁵ = 20647139 is a prime.

It is not a weakly prime, because it can be changed into another prime (20647177) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10323585 + 10323586.

It is an arithmetic number, because the mean of its divisors is an integer number (10323586).

Almost surely, 2^20647171 is an apocalyptic number.

20647171 is a deficient number, since it is larger than the sum of its proper divisors (1).

20647171 is an equidigital number, since it uses as much as digits as its factorization.

20647171 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2352, while the sum is 28.

The square root of 20647171 is about 4543.9158222837. The cubic root of 20647171 is about 274.3385580048.

The spelling of 20647171 in words is "twenty million, six hundred forty-seven thousand, one hundred seventy-one".