68171751981 has 8 divisors (see below), whose sum is σ = 100995188160. Its totient is φ = 45447834636.

The previous prime is 68171751979. The next prime is 68171752021. The reversal of 68171751981 is 18915717186.

It is not a de Polignac number, because 68171751981 - 2¹ = 68171751979 is a prime.

It is a super-2 number, since 2×68171751981² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68171751961) 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, 1262439825 + ... + 1262439878.

It is an arithmetic number, because the mean of its divisors is an integer number (12624398520).

Almost surely, 2^68171751981 is an apocalyptic number.

It is an amenable number.

68171751981 is a deficient number, since it is larger than the sum of its proper divisors (32823436179).

68171751981 is a wasteful number, since it uses less digits than its factorization.

68171751981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2524879712 (or 2524879706 counting only the distinct ones).

The product of its digits is 846720, while the sum is 54.

The spelling of 68171751981 in words is "sixty-eight billion, one hundred seventy-one million, seven hundred fifty-one thousand, nine hundred eighty-one".