68178781 has 12 divisors (see below), whose sum is σ = 75396636. Its totient is φ = 61603520.

The previous prime is 68178743. The next prime is 68178791. The reversal of 68178781 is 18787186.

It can be written as a sum of positive squares in 2 ways, for example, as 60310756 + 7868025 = 7766^2 + 2805^2 .

It is not a de Polignac number, because 68178781 - 2¹¹ = 68176733 is a prime.

It is a super-2 number, since 2×68178781² = 9296692357291922, which 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 (68178701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19305 + ... + 22561.

It is an arithmetic number, because the mean of its divisors is an integer number (6283053).

Almost surely, 2^68178781 is an apocalyptic number.

It is an amenable number.

68178781 is a deficient number, since it is larger than the sum of its proper divisors (7217855).

68178781 is a wasteful number, since it uses less digits than its factorization.

68178781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3452 (or 3441 counting only the distinct ones).

The product of its digits is 150528, while the sum is 46.

The square root of 68178781 is about 8257.0443259074. The cubic root of 68178781 is about 408.5229042118.

The spelling of 68178781 in words is "sixty-eight million, one hundred seventy-eight thousand, seven hundred eighty-one".