77684689 has 2 divisors, whose sum is σ = 77684690. Its totient is φ = 77684688.

The previous prime is 77684683. The next prime is 77684701. The reversal of 77684689 is 98648677.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 73616400 + 4068289 = 8580^2 + 2017^2 .

It is a cyclic number.

It is not a de Polignac number, because 77684689 - 2⁹ = 77684177 is a prime.

It is not a weakly prime, because it can be changed into another prime (77684683) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38842344 + 38842345.

It is an arithmetic number, because the mean of its divisors is an integer number (38842345).

Almost surely, 2^77684689 is an apocalyptic number.

It is an amenable number.

77684689 is a deficient number, since it is larger than the sum of its proper divisors (1).

77684689 is an equidigital number, since it uses as much as digits as its factorization.

77684689 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4064256, while the sum is 55.

The square root of 77684689 is about 8813.8918191682. The cubic root of 77684689 is about 426.6893571782.

The spelling of 77684689 in words is "seventy-seven million, six hundred eighty-four thousand, six hundred eighty-nine".