20717143 has 2 divisors, whose sum is σ = 20717144. Its totient is φ = 20717142.

The previous prime is 20717141. The next prime is 20717149. The reversal of 20717143 is 34171702.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20717143 - 2¹ = 20717141 is a prime.

Together with 20717141, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20717141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10358571 + 10358572.

It is an arithmetic number, because the mean of its divisors is an integer number (10358572).

Almost surely, 2^20717143 is an apocalyptic number.

20717143 is a deficient number, since it is larger than the sum of its proper divisors (1).

20717143 is an equidigital number, since it uses as much as digits as its factorization.

20717143 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1176, while the sum is 25.

The square root of 20717143 is about 4551.6088364445. The cubic root of 20717143 is about 274.6481141115.

Adding to 20717143 its reverse (34171702), we get a palindrome (54888845).

The spelling of 20717143 in words is "twenty million, seven hundred seventeen thousand, one hundred forty-three".