168643621751 has 16 divisors (see below), whose sum is σ = 189022442400. Its totient is φ = 149109367680.

The previous prime is 168643621687. The next prime is 168643621759. The reversal of 168643621751 is 157126346861.

It is a cyclic number.

It is not a de Polignac number, because 168643621751 - 2⁶ = 168643621687 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 168643621751.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (168643621759) 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 15 ways as a sum of consecutive naturals, for example, 956165 + ... + 1118721.

It is an arithmetic number, because the mean of its divisors is an integer number (11813902650).

Almost surely, 2^168643621751 is an apocalyptic number.

168643621751 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

168643621751 is a deficient number, since it is larger than the sum of its proper divisors (20378820649).

168643621751 is a wasteful number, since it uses less digits than its factorization.

168643621751 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165154.

The product of its digits is 1451520, while the sum is 50.

The spelling of 168643621751 in words is "one hundred sixty-eight billion, six hundred forty-three million, six hundred twenty-one thousand, seven hundred fifty-one".