168404513781 has 16 divisors (see below), whose sum is σ = 257256355968. Its totient is φ = 95991168000.

The previous prime is 168404513779. The next prime is 168404513789. The reversal of 168404513781 is 187315404861.

It is not a de Polignac number, because 168404513781 - 2¹ = 168404513779 is a prime.

It is a super-2 number, since 2×168404513781² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 168404513781.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (168404513789) 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, 9990660 + ... + 10007501.

It is an arithmetic number, because the mean of its divisors is an integer number (16078522248).

Almost surely, 2^168404513781 is an apocalyptic number.

It is an amenable number.

168404513781 is a deficient number, since it is larger than the sum of its proper divisors (88851842187).

168404513781 is a wasteful number, since it uses less digits than its factorization.

168404513781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19998572.

The product of its (nonzero) digits is 645120, while the sum is 48.

The spelling of 168404513781 in words is "one hundred sixty-eight billion, four hundred four million, five hundred thirteen thousand, seven hundred eighty-one".