7728140561 has 2 divisors, whose sum is σ = 7728140562. Its totient is φ = 7728140560.

The previous prime is 7728140549. The next prime is 7728140611. The reversal of 7728140561 is 1650418277.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4922425600 + 2805714961 = 70160^2 + 52969^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7728140561 is a prime.

It is not a weakly prime, because it can be changed into another prime (7728140501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3864070280 + 3864070281.

It is an arithmetic number, because the mean of its divisors is an integer number (3864070281).

Almost surely, 2^7728140561 is an apocalyptic number.

It is an amenable number.

7728140561 is a deficient number, since it is larger than the sum of its proper divisors (1).

7728140561 is an equidigital number, since it uses as much as digits as its factorization.

7728140561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 94080, while the sum is 41.

The square root of 7728140561 is about 87909.8433680780. The cubic root of 7728140561 is about 1977.0834659007.

The spelling of 7728140561 in words is "seven billion, seven hundred twenty-eight million, one hundred forty thousand, five hundred sixty-one".