68240681 has 2 divisors, whose sum is σ = 68240682. Its totient is φ = 68240680.

The previous prime is 68240633. The next prime is 68240713. The reversal of 68240681 is 18604286.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 38440000 + 29800681 = 6200^2 + 5459^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-68240681 is a prime.

It is a super-2 number, since 2×68240681² = 9313581086687522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (68240621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34120340 + 34120341.

It is an arithmetic number, because the mean of its divisors is an integer number (34120341).

Almost surely, 2^68240681 is an apocalyptic number.

It is an amenable number.

68240681 is a deficient number, since it is larger than the sum of its proper divisors (1).

68240681 is an equidigital number, since it uses as much as digits as its factorization.

68240681 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18432, while the sum is 35.

The square root of 68240681 is about 8260.7917901373. The cubic root of 68240681 is about 408.6465004311.

It can be divided in two parts, 68240 and 681, that added together give a cube (68921 = 41³).

The spelling of 68240681 in words is "sixty-eight million, two hundred forty thousand, six hundred eighty-one".