8168858401681 has 8 divisors (see below), whose sum is σ = 8180686650024. Its totient is φ = 8157033025920.

The previous prime is 8168858401621. The next prime is 8168858401699. The reversal of 8168858401681 is 1861048588618.

It can be written as a sum of positive squares in 4 ways, for example, as 2364536667025 + 5804321734656 = 1537705^2 + 2409216^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 8168858401681 - 2²¹ = 8168856304529 is a prime.

It is a super-2 number, since 2×8168858401681² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8168858401621) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5006431 + ... + 6434443.

It is an arithmetic number, because the mean of its divisors is an integer number (1022585831253).

Almost surely, 2^{8168858401681} is an apocalyptic number.

It is an amenable number.

8168858401681 is a deficient number, since it is larger than the sum of its proper divisors (11828248343).

8168858401681 is a wasteful number, since it uses less digits than its factorization.

8168858401681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1436291.

The product of its (nonzero) digits is 23592960, while the sum is 64.

The spelling of 8168858401681 in words is "eight trillion, one hundred sixty-eight billion, eight hundred fifty-eight million, four hundred one thousand, six hundred eighty-one".