217843158861 has 8 divisors (see below), whose sum is σ = 322730605760. Its totient is φ = 145228772556.

The previous prime is 217843158823. The next prime is 217843158881. The reversal of 217843158861 is 168851348712.

217843158861 is a `hidden beast` number, since 2 + 1 + 78 + 431 + 5 + 88 + 61 = 666.

It is not a de Polignac number, because 217843158861 - 2¹⁰ = 217843157837 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 217843158798 and 217843158807.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (217843158821) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4034132545 + ... + 4034132598.

It is an arithmetic number, because the mean of its divisors is an integer number (40341325720).

Almost surely, 2^217843158861 is an apocalyptic number.

It is an amenable number.

217843158861 is a deficient number, since it is larger than the sum of its proper divisors (104887446899).

217843158861 is an equidigital number, since it uses as much as digits as its factorization.

217843158861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8068265152 (or 8068265146 counting only the distinct ones).

The product of its digits is 2580480, while the sum is 54.

The spelling of 217843158861 in words is "two hundred seventeen billion, eight hundred forty-three million, one hundred fifty-eight thousand, eight hundred sixty-one".