168866271781 has 16 divisors (see below), whose sum is σ = 175420324800. Its totient is φ = 162361721088.

The previous prime is 168866271737. The next prime is 168866271829. The reversal of 168866271781 is 187172668861.

It is a cyclic number.

It is not a de Polignac number, because 168866271781 - 2¹⁹ = 168865747493 is a prime.

It is a super-2 number, since 2×168866271781² (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 (168866271701) 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, 14578050 + ... + 14589628.

It is an arithmetic number, because the mean of its divisors is an integer number (10963770300).

Almost surely, 2^168866271781 is an apocalyptic number.

It is an amenable number.

168866271781 is a deficient number, since it is larger than the sum of its proper divisors (6554053019).

168866271781 is a wasteful number, since it uses less digits than its factorization.

168866271781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13668.

The product of its digits is 10838016, while the sum is 61.

The spelling of 168866271781 in words is "one hundred sixty-eight billion, eight hundred sixty-six million, two hundred seventy-one thousand, seven hundred eighty-one".