68278458781 has 6 divisors (see below), whose sum is σ = 73934662650. Its totient is φ = 63026269488.

The previous prime is 68278458751. The next prime is 68278458791. The reversal of 68278458781 is 18785487286.

It can be written as a sum of positive squares in 3 ways, for example, as 6132456100 + 62146002681 = 78310^2 + 249291^2 .

It is not a de Polignac number, because 68278458781 - 2⁵ = 68278458749 is a prime.

It is a super-2 number, since 2×68278458781² (a number of 22 digits) 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 (68278458751) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 202007106 + ... + 202007443.

It is an arithmetic number, because the mean of its divisors is an integer number (12322443775).

Almost surely, 2^68278458781 is an apocalyptic number.

It is an amenable number.

68278458781 is a deficient number, since it is larger than the sum of its proper divisors (5656203869).

68278458781 is a wasteful number, since it uses less digits than its factorization.

68278458781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 404014575 (or 404014562 counting only the distinct ones).

The product of its digits is 48168960, while the sum is 64.

The spelling of 68278458781 in words is "sixty-eight billion, two hundred seventy-eight million, four hundred fifty-eight thousand, seven hundred eighty-one".