68640617 has 2 divisors, whose sum is σ = 68640618. Its totient is φ = 68640616.

The previous prime is 68640613. The next prime is 68640619. The reversal of 68640617 is 71604686.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 68293696 + 346921 = 8264^2 + 589^2 .

It is a cyclic number.

It is not a de Polignac number, because 68640617 - 2² = 68640613 is a prime.

Together with 68640619, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (68640613) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34320308 + 34320309.

It is an arithmetic number, because the mean of its divisors is an integer number (34320309).

Almost surely, 2^68640617 is an apocalyptic number.

It is an amenable number.

68640617 is a deficient number, since it is larger than the sum of its proper divisors (1).

68640617 is an equidigital number, since it uses as much as digits as its factorization.

68640617 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 48384, while the sum is 38.

The square root of 68640617 is about 8284.9633071004. The cubic root of 68640617 is about 409.4432598101.

The spelling of 68640617 in words is "sixty-eight million, six hundred forty thousand, six hundred seventeen".