216581543 has 2 divisors, whose sum is σ = 216581544. Its totient is φ = 216581542.

The previous prime is 216581539. The next prime is 216581549. The reversal of 216581543 is 345185612.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 216581543 - 2² = 216581539 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (216581549) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108290771 + 108290772.

It is an arithmetic number, because the mean of its divisors is an integer number (108290772).

Almost surely, 2^216581543 is an apocalyptic number.

216581543 is a deficient number, since it is larger than the sum of its proper divisors (1).

216581543 is an equidigital number, since it uses as much as digits as its factorization.

216581543 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 28800, while the sum is 35.

The square root of 216581543 is about 14716.7096526364. The cubic root of 216581543 is about 600.5379832200.

The spelling of 216581543 in words is "two hundred sixteen million, five hundred eighty-one thousand, five hundred forty-three".