77728073 has 2 divisors, whose sum is σ = 77728074. Its totient is φ = 77728072.

The previous prime is 77728019. The next prime is 77728111. The reversal of 77728073 is 37082777.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 77651344 + 76729 = 8812^2 + 277^2 .

It is an emirp because it is prime and its reverse (37082777) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 77728073 - 2²⁶ = 10619209 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 77728073.

It is not a weakly prime, because it can be changed into another prime (77778073) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38864036 + 38864037.

It is an arithmetic number, because the mean of its divisors is an integer number (38864037).

Almost surely, 2^77728073 is an apocalyptic number.

It is an amenable number.

77728073 is a deficient number, since it is larger than the sum of its proper divisors (1).

77728073 is an equidigital number, since it uses as much as digits as its factorization.

77728073 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 115248, while the sum is 41.

The square root of 77728073 is about 8816.3525904991. The cubic root of 77728073 is about 426.7687724245.

The spelling of 77728073 in words is "seventy-seven million, seven hundred twenty-eight thousand, seventy-three".