68383781 has 2 divisors, whose sum is σ = 68383782. Its totient is φ = 68383780.

The previous prime is 68383729. The next prime is 68383789. The reversal of 68383781 is 18738386.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 59136100 + 9247681 = 7690^2 + 3041^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-68383781 is a prime.

It is a super-2 number, since 2×68383781² = 9352683007711922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (68383789) 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, 34191890 + 34191891.

It is an arithmetic number, because the mean of its divisors is an integer number (34191891).

Almost surely, 2^68383781 is an apocalyptic number.

It is an amenable number.

68383781 is a deficient number, since it is larger than the sum of its proper divisors (1).

68383781 is an equidigital number, since it uses as much as digits as its factorization.

68383781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 193536, while the sum is 44.

The square root of 68383781 is about 8269.4486515124. The cubic root of 68383781 is about 408.9319434908.

The spelling of 68383781 in words is "sixty-eight million, three hundred eighty-three thousand, seven hundred eighty-one".