77705689 has 2 divisors, whose sum is σ = 77705690. Its totient is φ = 77705688.

The previous prime is 77705671. The next prime is 77705713. The reversal of 77705689 is 98650777.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 66145689 + 11560000 = 8133^2 + 3400^2 .

It is a cyclic number.

It is not a de Polignac number, because 77705689 - 2²³ = 69317081 is a prime.

It is not a weakly prime, because it can be changed into another prime (77705629) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38852844 + 38852845.

It is an arithmetic number, because the mean of its divisors is an integer number (38852845).

Almost surely, 2^77705689 is an apocalyptic number.

It is an amenable number.

77705689 is a deficient number, since it is larger than the sum of its proper divisors (1).

77705689 is an equidigital number, since it uses as much as digits as its factorization.

77705689 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 740880, while the sum is 49.

The square root of 77705689 is about 8815.0830398811. The cubic root of 77705689 is about 426.7278017731.

The spelling of 77705689 in words is "seventy-seven million, seven hundred five thousand, six hundred eighty-nine".