7705728389 has 2 divisors, whose sum is σ = 7705728390. Its totient is φ = 7705728388.

The previous prime is 7705728377. The next prime is 7705728451. The reversal of 7705728389 is 9838275077.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7699185025 + 6543364 = 87745^2 + 2558^2 .

It is an emirp because it is prime and its reverse (9838275077) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7705728389 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7705728889) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3852864194 + 3852864195.

It is an arithmetic number, because the mean of its divisors is an integer number (3852864195).

Almost surely, 2^7705728389 is an apocalyptic number.

It is an amenable number.

7705728389 is a deficient number, since it is larger than the sum of its proper divisors (1).

7705728389 is an equidigital number, since it uses as much as digits as its factorization.

7705728389 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5927040, while the sum is 56.

The square root of 7705728389 is about 87782.2783311074. The cubic root of 7705728389 is about 1975.1703865392.

The spelling of 7705728389 in words is "seven billion, seven hundred five million, seven hundred twenty-eight thousand, three hundred eighty-nine".