217987813179 has 24 divisors (see below), whose sum is σ = 316739145632. Its totient is φ = 144463772160.

The previous prime is 217987813157. The next prime is 217987813229. The reversal of 217987813179 is 971318789712.

It is not a de Polignac number, because 217987813179 - 2⁹ = 217987812667 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (217987813679) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4198194 + ... + 4249800.

Almost surely, 2^217987813179 is an apocalyptic number.

217987813179 is a deficient number, since it is larger than the sum of its proper divisors (98751332453).

217987813179 is a wasteful number, since it uses less digits than its factorization.

217987813179 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54387 (or 54384 counting only the distinct ones).

The product of its digits is 10668672, while the sum is 63.

The spelling of 217987813179 in words is "two hundred seventeen billion, nine hundred eighty-seven million, eight hundred thirteen thousand, one hundred seventy-nine".