68788781 has 2 divisors, whose sum is σ = 68788782. Its totient is φ = 68788780.

The previous prime is 68788763. The next prime is 68788787. The reversal of 68788781 is 18788786.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 67798756 + 990025 = 8234^2 + 995^2 .

It is a cyclic number.

It is not a de Polignac number, because 68788781 - 2¹⁴ = 68772397 is a prime.

It is a super-2 number, since 2×68788781² = 9463792782931922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (68788787) 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 as a sum of consecutive naturals, namely, 34394390 + 34394391.

It is an arithmetic number, because the mean of its divisors is an integer number (34394391).

Almost surely, 2^68788781 is an apocalyptic number.

It is an amenable number.

68788781 is a deficient number, since it is larger than the sum of its proper divisors (1).

68788781 is an equidigital number, since it uses as much as digits as its factorization.

68788781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1204224, while the sum is 53.

The square root of 68788781 is about 8293.9002284812. The cubic root of 68788781 is about 409.7376489382.

The spelling of 68788781 in words is "sixty-eight million, seven hundred eighty-eight thousand, seven hundred eighty-one".