71728777 has 2 divisors, whose sum is σ = 71728778. Its totient is φ = 71728776.

The previous prime is 71728771. The next prime is 71728799. The reversal of 71728777 is 77782717.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 36433296 + 35295481 = 6036^2 + 5941^2 .

It is an emirp because it is prime and its reverse (77782717) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-71728777 is a prime.

It is not a weakly prime, because it can be changed into another prime (71728771) 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, 35864388 + 35864389.

It is an arithmetic number, because the mean of its divisors is an integer number (35864389).

Almost surely, 2^71728777 is an apocalyptic number.

It is an amenable number.

71728777 is a deficient number, since it is larger than the sum of its proper divisors (1).

71728777 is an equidigital number, since it uses as much as digits as its factorization.

71728777 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 268912, while the sum is 46.

The square root of 71728777 is about 8469.2843263171. The cubic root of 71728777 is about 415.4937308478.

The spelling of 71728777 in words is "seventy-one million, seven hundred twenty-eight thousand, seven hundred seventy-seven".