68444173681 has 4 divisors (see below), whose sum is σ = 73709110132. Its totient is φ = 63179237232.

The previous prime is 68444173631. The next prime is 68444173703. The reversal of 68444173681 is 18637144486.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18637144486 = 2 ⋅9318572243.

It can be written as a sum of positive squares in 2 ways, for example, as 7701642081 + 60742531600 = 87759^2 + 246460^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-68444173681 is a prime.

It is a super-2 number, since 2×68444173681² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (68444173631) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2632468206 + ... + 2632468231.

It is an arithmetic number, because the mean of its divisors is an integer number (18427277533).

Almost surely, 2^68444173681 is an apocalyptic number.

It is an amenable number.

68444173681 is a deficient number, since it is larger than the sum of its proper divisors (5264936451).

68444173681 is a wasteful number, since it uses less digits than its factorization.

68444173681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5264936450.

The product of its digits is 3096576, while the sum is 52.

The spelling of 68444173681 in words is "sixty-eight billion, four hundred forty-four million, one hundred seventy-three thousand, six hundred eighty-one".