217542045071 has 4 divisors (see below), whose sum is σ = 234276048552. Its totient is φ = 200808041592.

The previous prime is 217542045029. The next prime is 217542045073. The reversal of 217542045071 is 170540245712.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 217542045071 - 2¹⁰ = 217542044047 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (217542045073) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8367001721 + ... + 8367001746.

It is an arithmetic number, because the mean of its divisors is an integer number (58569012138).

Almost surely, 2^217542045071 is an apocalyptic number.

217542045071 is a deficient number, since it is larger than the sum of its proper divisors (16734003481).

217542045071 is a wasteful number, since it uses less digits than its factorization.

217542045071 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16734003480.

The product of its (nonzero) digits is 78400, while the sum is 38.

The spelling of 217542045071 in words is "two hundred seventeen billion, five hundred forty-two million, forty-five thousand, seventy-one".