67765991 has 2 divisors, whose sum is σ = 67765992. Its totient is φ = 67765990.

The previous prime is 67765933. The next prime is 67765993. The reversal of 67765991 is 19956776.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 67765991 - 2²⁶ = 657127 is a prime.

It is a Sophie Germain prime.

Together with 67765993, 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 (67765993) 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, 33882995 + 33882996.

It is an arithmetic number, because the mean of its divisors is an integer number (33882996).

Almost surely, 2^67765991 is an apocalyptic number.

67765991 is a deficient number, since it is larger than the sum of its proper divisors (1).

67765991 is an equidigital number, since it uses as much as digits as its factorization.

67765991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 714420, while the sum is 50.

The square root of 67765991 is about 8232.0101433368. The cubic root of 67765991 is about 407.6967642227.

The spelling of 67765991 in words is "sixty-seven million, seven hundred sixty-five thousand, nine hundred ninety-one".