168806497391 has 6 divisors (see below), whose sum is σ = 196366741920. Its totient is φ = 144691283436.

The previous prime is 168806497357. The next prime is 168806497403. The reversal of 168806497391 is 193794608861.

It is not a de Polignac number, because 168806497391 - 2²⁶ = 168739388527 is a prime.

It is a super-2 number, since 2×168806497391² (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 (168806494391) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1722515231 + ... + 1722515328.

It is an arithmetic number, because the mean of its divisors is an integer number (32727790320).

Almost surely, 2^168806497391 is an apocalyptic number.

168806497391 is a deficient number, since it is larger than the sum of its proper divisors (27560244529).

168806497391 is an equidigital number, since it uses as much as digits as its factorization.

168806497391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3445030573 (or 3445030566 counting only the distinct ones).

The product of its (nonzero) digits is 15676416, while the sum is 62.

The spelling of 168806497391 in words is "one hundred sixty-eight billion, eight hundred six million, four hundred ninety-seven thousand, three hundred ninety-one".