217142543 has 2 divisors, whose sum is σ = 217142544. Its totient is φ = 217142542.

The previous prime is 217142539. The next prime is 217142557. The reversal of 217142543 is 345241712.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 217142543 - 2² = 217142539 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (217142533) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108571271 + 108571272.

It is an arithmetic number, because the mean of its divisors is an integer number (108571272).

Almost surely, 2^217142543 is an apocalyptic number.

217142543 is a deficient number, since it is larger than the sum of its proper divisors (1).

217142543 is an equidigital number, since it uses as much as digits as its factorization.

217142543 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6720, while the sum is 29.

The square root of 217142543 is about 14735.7572930610. The cubic root of 217142543 is about 601.0560503574.

The spelling of 217142543 in words is "two hundred seventeen million, one hundred forty-two thousand, five hundred forty-three".