68818081 has 4 divisors (see below), whose sum is σ = 69016752. Its totient is φ = 68619412.

The previous prime is 68818063. The next prime is 68818097. The reversal of 68818081 is 18081886.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 18081886 = 2 ⋅9040943.

It is a cyclic number.

It is not a de Polignac number, because 68818081 - 2⁹ = 68817569 is a prime.

It is a super-2 number, since 2×68818081² = 9471856545045122, which contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (68818381) 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, 98815 + ... + 99508.

It is an arithmetic number, because the mean of its divisors is an integer number (17254188).

Almost surely, 2^68818081 is an apocalyptic number.

It is an amenable number.

68818081 is a deficient number, since it is larger than the sum of its proper divisors (198671).

68818081 is a wasteful number, since it uses less digits than its factorization.

68818081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 198670.

The product of its (nonzero) digits is 24576, while the sum is 40.

The square root of 68818081 is about 8295.6663987892. Note that the first 3 decimals coincide. The cubic root of 68818081 is about 409.7958154435.

It can be divided in two parts, 688 and 18081, that added together give a square (18769 = 137²).

The spelling of 68818081 in words is "sixty-eight million, eight hundred eighteen thousand, eighty-one".