68068991 has 2 divisors, whose sum is σ = 68068992. Its totient is φ = 68068990.

The previous prime is 68068981. The next prime is 68068993. The reversal of 68068991 is 19986086.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 68068991 - 2⁶ = 68068927 is a prime.

Together with 68068993, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (68068993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34034495 + 34034496.

It is an arithmetic number, because the mean of its divisors is an integer number (34034496).

Almost surely, 2^68068991 is an apocalyptic number.

68068991 is a deficient number, since it is larger than the sum of its proper divisors (1).

68068991 is an equidigital number, since it uses as much as digits as its factorization.

68068991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 186624, while the sum is 47.

The square root of 68068991 is about 8250.3933845605. The cubic root of 68068991 is about 408.3035015089.

The spelling of 68068991 in words is "sixty-eight million, sixty-eight thousand, nine hundred ninety-one".