217511742479 has 4 divisors (see below), whose sum is σ = 217567276584. Its totient is φ = 217456208376.

The previous prime is 217511742467. The next prime is 217511742521. The reversal of 217511742479 is 974247115712.

217511742479 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 217511742479 - 2²⁰ = 217510693903 is a prime.

It is a super-2 number, since 2×217511742479² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (217511342479) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27761177 + ... + 27769010.

It is an arithmetic number, because the mean of its divisors is an integer number (54391819146).

Almost surely, 2^217511742479 is an apocalyptic number.

217511742479 is a deficient number, since it is larger than the sum of its proper divisors (55534105).

217511742479 is an equidigital number, since it uses as much as digits as its factorization.

217511742479 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55534104.

The product of its digits is 987840, while the sum is 50.

The spelling of 217511742479 in words is "two hundred seventeen billion, five hundred eleven million, seven hundred forty-two thousand, four hundred seventy-nine".