217071117155 has 4 divisors (see below), whose sum is σ = 260485340592. Its totient is φ = 173656893720.

The previous prime is 217071117149. The next prime is 217071117163. The reversal of 217071117155 is 551711170712.

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

It is not a de Polignac number, because 217071117155 - 2⁴ = 217071117139 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21707111711 + ... + 21707111720.

It is an arithmetic number, because the mean of its divisors is an integer number (65121335148).

Almost surely, 2^217071117155 is an apocalyptic number.

217071117155 is a deficient number, since it is larger than the sum of its proper divisors (43414223437).

217071117155 is an equidigital number, since it uses as much as digits as its factorization.

217071117155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43414223436.

The product of its (nonzero) digits is 17150, while the sum is 38.

Adding to 217071117155 its reverse (551711170712), we get a palindrome (768782287867).

The spelling of 217071117155 in words is "two hundred seventeen billion, seventy-one million, one hundred seventeen thousand, one hundred fifty-five".