68091281 has 2 divisors, whose sum is σ = 68091282. Its totient is φ = 68091280.

The previous prime is 68091263. The next prime is 68091301. The reversal of 68091281 is 18219086.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 52417600 + 15673681 = 7240^2 + 3959^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-68091281 is a prime.

It is a super-2 number, since 2×68091281² = 9272845096441922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (68091241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34045640 + 34045641.

It is an arithmetic number, because the mean of its divisors is an integer number (34045641).

Almost surely, 2^68091281 is an apocalyptic number.

It is an amenable number.

68091281 is a deficient number, since it is larger than the sum of its proper divisors (1).

68091281 is an equidigital number, since it uses as much as digits as its factorization.

68091281 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6912, while the sum is 35.

The square root of 68091281 is about 8251.7441186697. The cubic root of 68091281 is about 408.3480645896.

The spelling of 68091281 in words is "sixty-eight million, ninety-one thousand, two hundred eighty-one".