20716543 has 2 divisors, whose sum is σ = 20716544. Its totient is φ = 20716542.

The previous prime is 20716541. The next prime is 20716561. The reversal of 20716543 is 34561702.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20716543 - 2¹ = 20716541 is a prime.

Together with 20716541, 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 (20716541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10358271 + 10358272.

It is an arithmetic number, because the mean of its divisors is an integer number (10358272).

Almost surely, 2^20716543 is an apocalyptic number.

20716543 is a deficient number, since it is larger than the sum of its proper divisors (1).

20716543 is an equidigital number, since it uses as much as digits as its factorization.

20716543 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5040, while the sum is 28.

The square root of 20716543 is about 4551.5429252068. The cubic root of 20716543 is about 274.6454626767.

The spelling of 20716543 in words is "twenty million, seven hundred sixteen thousand, five hundred forty-three".