68128513 has 2 divisors, whose sum is σ = 68128514. Its totient is φ = 68128512.

The previous prime is 68128477. The next prime is 68128517. The reversal of 68128513 is 31582186.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 38229489 + 29899024 = 6183^2 + 5468^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-68128513 is a prime.

It is not a weakly prime, because it can be changed into another prime (68128517) 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, 34064256 + 34064257.

It is an arithmetic number, because the mean of its divisors is an integer number (34064257).

Almost surely, 2^68128513 is an apocalyptic number.

It is an amenable number.

68128513 is a deficient number, since it is larger than the sum of its proper divisors (1).

68128513 is an equidigital number, since it uses as much as digits as its factorization.

68128513 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11520, while the sum is 34.

The square root of 68128513 is about 8253.9998182699. Note that the first 3 decimals coincide. The cubic root of 68128513 is about 408.4224786441.

The spelling of 68128513 in words is "sixty-eight million, one hundred twenty-eight thousand, five hundred thirteen".