77646165455609 has 2 divisors, whose sum is σ = 77646165455610. Its totient is φ = 77646165455608.

The previous prime is 77646165455569. The next prime is 77646165455689. The reversal of 77646165455609 is 90655456164677.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 38985787699600 + 38660377756009 = 6243860^2 + 6217747^2 .

It is a cyclic number.

It is not a de Polignac number, because 77646165455609 - 2²⁰ = 77646164407033 is a prime.

It is not a weakly prime, because it can be changed into another prime (77646165455689) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38823082727804 + 38823082727805.

It is an arithmetic number, because the mean of its divisors is an integer number (38823082727805).

Almost surely, 2^{77646165455609} is an apocalyptic number.

It is an amenable number.

77646165455609 is a deficient number, since it is larger than the sum of its proper divisors (1).

77646165455609 is an equidigital number, since it uses as much as digits as its factorization.

77646165455609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1143072000, while the sum is 71.

The spelling of 77646165455609 in words is "seventy-seven trillion, six hundred forty-six billion, one hundred sixty-five million, four hundred fifty-five thousand, six hundred nine".