68140991 has 2 divisors, whose sum is σ = 68140992. Its totient is φ = 68140990.

The previous prime is 68140949. The next prime is 68141027. The reversal of 68140991 is 19904186.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 68140991 - 2¹⁸ = 67878847 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (68140291) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34070495 + 34070496.

It is an arithmetic number, because the mean of its divisors is an integer number (34070496).

Almost surely, 2^68140991 is an apocalyptic number.

68140991 is a deficient number, since it is larger than the sum of its proper divisors (1).

68140991 is an equidigital number, since it uses as much as digits as its factorization.

68140991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15552, while the sum is 38.

The square root of 68140991 is about 8254.7556596183. The cubic root of 68140991 is about 408.4474118395.

The spelling of 68140991 in words is "sixty-eight million, one hundred forty thousand, nine hundred ninety-one".