68681689 has 2 divisors, whose sum is σ = 68681690. Its totient is φ = 68681688.

The previous prime is 68681687. The next prime is 68681719. The reversal of 68681689 is 98618686.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 56550400 + 12131289 = 7520^2 + 3483^2 .

It is a cyclic number.

It is not a de Polignac number, because 68681689 - 2¹ = 68681687 is a prime.

Together with 68681687, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (68681681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34340844 + 34340845.

It is an arithmetic number, because the mean of its divisors is an integer number (34340845).

Almost surely, 2^68681689 is an apocalyptic number.

It is an amenable number.

68681689 is a deficient number, since it is larger than the sum of its proper divisors (1).

68681689 is an equidigital number, since it uses as much as digits as its factorization.

68681689 is an evil number, because the sum of its binary digits is even.

The product of its digits is 995328, while the sum is 52.

The square root of 68681689 is about 8287.4416438368. The cubic root of 68681689 is about 409.5249087485.

The spelling of 68681689 in words is "sixty-eight million, six hundred eighty-one thousand, six hundred eighty-nine".