21716143 has 2 divisors, whose sum is σ = 21716144. Its totient is φ = 21716142.

The previous prime is 21716137. The next prime is 21716159. The reversal of 21716143 is 34161712.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21716143 - 2¹⁷ = 21585071 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21711143) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10858071 + 10858072.

It is an arithmetic number, because the mean of its divisors is an integer number (10858072).

Almost surely, 2^21716143 is an apocalyptic number.

21716143 is a deficient number, since it is larger than the sum of its proper divisors (1).

21716143 is an equidigital number, since it uses as much as digits as its factorization.

21716143 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1008, while the sum is 25.

The square root of 21716143 is about 4660.0582614384. The cubic root of 21716143 is about 278.9935936317.

Adding to 21716143 its reverse (34161712), we get a palindrome (55877855).

The spelling of 21716143 in words is "twenty-one million, seven hundred sixteen thousand, one hundred forty-three".