68399561 has 2 divisors, whose sum is σ = 68399562. Its totient is φ = 68399560.

The previous prime is 68399557. The next prime is 68399567. The reversal of 68399561 is 16599386.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 66015625 + 2383936 = 8125^2 + 1544^2 .

It is a cyclic number.

It is not a de Polignac number, because 68399561 - 2² = 68399557 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (68399567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34199780 + 34199781.

It is an arithmetic number, because the mean of its divisors is an integer number (34199781).

Almost surely, 2^68399561 is an apocalyptic number.

It is an amenable number.

68399561 is a deficient number, since it is larger than the sum of its proper divisors (1).

68399561 is an equidigital number, since it uses as much as digits as its factorization.

68399561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 349920, while the sum is 47.

The square root of 68399561 is about 8270.4027108721. The cubic root of 68399561 is about 408.9633956357.

The spelling of 68399561 in words is "sixty-eight million, three hundred ninety-nine thousand, five hundred sixty-one".