171685216879 has 16 divisors (see below), whose sum is σ = 188044835616. Its totient is φ = 155451369600.

The previous prime is 171685216867. The next prime is 171685216891. The reversal of 171685216879 is 978612586171.

It is an interprime number because it is at equal distance from previous prime (171685216867) and next prime (171685216891).

It is a cyclic number.

It is not a de Polignac number, because 171685216879 - 2¹⁷ = 171685085807 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (171685216819) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8634409 + ... + 8654269.

It is an arithmetic number, because the mean of its divisors is an integer number (11752802226).

Almost surely, 2^171685216879 is an apocalyptic number.

171685216879 is a deficient number, since it is larger than the sum of its proper divisors (16359618737).

171685216879 is a wasteful number, since it uses less digits than its factorization.

171685216879 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22986.

The product of its digits is 10160640, while the sum is 61.

The spelling of 171685216879 in words is "one hundred seventy-one billion, six hundred eighty-five million, two hundred sixteen thousand, eight hundred seventy-nine".