168855131391 has 4 divisors (see below), whose sum is σ = 225140175192. Its totient is φ = 112570087592.

The previous prime is 168855131297. The next prime is 168855131407. The reversal of 168855131391 is 193131558861.

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 168855131391 - 2¹⁴ = 168855115007 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (168855131791) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28142521896 + ... + 28142521901.

It is an arithmetic number, because the mean of its divisors is an integer number (56285043798).

Almost surely, 2^168855131391 is an apocalyptic number.

168855131391 is a deficient number, since it is larger than the sum of its proper divisors (56285043801).

168855131391 is an equidigital number, since it uses as much as digits as its factorization.

168855131391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56285043800.

The product of its digits is 777600, while the sum is 51.

The spelling of 168855131391 in words is "one hundred sixty-eight billion, eight hundred fifty-five million, one hundred thirty-one thousand, three hundred ninety-one".