20572171 has 2 divisors, whose sum is σ = 20572172. Its totient is φ = 20572170.

The previous prime is 20572163. The next prime is 20572177. The reversal of 20572171 is 17127502.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20572171 - 2³ = 20572163 is a prime.

It is not a weakly prime, because it can be changed into another prime (20572177) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10286085 + 10286086.

It is an arithmetic number, because the mean of its divisors is an integer number (10286086).

Almost surely, 2^20572171 is an apocalyptic number.

20572171 is a deficient number, since it is larger than the sum of its proper divisors (1).

20572171 is an equidigital number, since it uses as much as digits as its factorization.

20572171 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 980, while the sum is 25.

The square root of 20572171 is about 4535.6555204292. The cubic root of 20572171 is about 274.0059804758.

Adding to 20572171 its reverse (17127502), we get a palindrome (37699673).

The spelling of 20572171 in words is "twenty million, five hundred seventy-two thousand, one hundred seventy-one".