77064381918661 has 2 divisors, whose sum is σ = 77064381918662. Its totient is φ = 77064381918660.

The previous prime is 77064381918599. The next prime is 77064381918691. The reversal of 77064381918661 is 16681918346077.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 43789585716900 + 33274796201761 = 6617370^2 + 5768431^2 .

It is a cyclic number.

It is not a de Polignac number, because 77064381918661 - 2⁹ = 77064381918149 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77064381918691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38532190959330 + 38532190959331.

It is an arithmetic number, because the mean of its divisors is an integer number (38532190959331).

Almost surely, 2^{77064381918661} is an apocalyptic number.

It is an amenable number.

77064381918661 is a deficient number, since it is larger than the sum of its proper divisors (1).

77064381918661 is an equidigital number, since it uses as much as digits as its factorization.

77064381918661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 73156608, while the sum is 67.

The spelling of 77064381918661 in words is "seventy-seven trillion, sixty-four billion, three hundred eighty-one million, nine hundred eighteen thousand, six hundred sixty-one".