77318729 has 2 divisors, whose sum is σ = 77318730. Its totient is φ = 77318728.

The previous prime is 77318719. The next prime is 77318741. The reversal of 77318729 is 92781377.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 73136704 + 4182025 = 8552^2 + 2045^2 .

It is a cyclic number.

It is not a de Polignac number, because 77318729 - 2⁸ = 77318473 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 77318729.

It is not a weakly prime, because it can be changed into another prime (77318719) 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, 38659364 + 38659365.

It is an arithmetic number, because the mean of its divisors is an integer number (38659365).

Almost surely, 2^77318729 is an apocalyptic number.

It is an amenable number.

77318729 is a deficient number, since it is larger than the sum of its proper divisors (1).

77318729 is an equidigital number, since it uses as much as digits as its factorization.

77318729 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 148176, while the sum is 44.

The square root of 77318729 is about 8793.1069025686. The cubic root of 77318729 is about 426.0182807881.

The spelling of 77318729 in words is "seventy-seven million, three hundred eighteen thousand, seven hundred twenty-nine".