67781601779 has 2 divisors, whose sum is σ = 67781601780. Its totient is φ = 67781601778.

The previous prime is 67781601721. The next prime is 67781601821. The reversal of 67781601779 is 97710618776.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 67781601779 - 2³² = 63486634483 is a prime.

It is not a weakly prime, because it can be changed into another prime (67781601079) 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, 33890800889 + 33890800890.

It is an arithmetic number, because the mean of its divisors is an integer number (33890800890).

Almost surely, 2^67781601779 is an apocalyptic number.

67781601779 is a deficient number, since it is larger than the sum of its proper divisors (1).

67781601779 is an equidigital number, since it uses as much as digits as its factorization.

67781601779 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6223392, while the sum is 59.

The spelling of 67781601779 in words is "sixty-seven billion, seven hundred eighty-one million, six hundred one thousand, seven hundred seventy-nine".