20315171 has 2 divisors, whose sum is σ = 20315172. Its totient is φ = 20315170.

The previous prime is 20315147. The next prime is 20315173. The reversal of 20315171 is 17151302.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20315171 is a prime.

Together with 20315173, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20315173) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10157585 + 10157586.

It is an arithmetic number, because the mean of its divisors is an integer number (10157586).

Almost surely, 2^20315171 is an apocalyptic number.

20315171 is a deficient number, since it is larger than the sum of its proper divisors (1).

20315171 is an equidigital number, since it uses as much as digits as its factorization.

20315171 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 210, while the sum is 20.

The square root of 20315171 is about 4507.2354054342. The cubic root of 20315171 is about 272.8601796684.

Adding to 20315171 its reverse (17151302), we get a palindrome (37466473).

The spelling of 20315171 in words is "twenty million, three hundred fifteen thousand, one hundred seventy-one".