775728001681 has 2 divisors, whose sum is σ = 775728001682. Its totient is φ = 775728001680.

The previous prime is 775728001663. The next prime is 775728001687. The reversal of 775728001681 is 186100827577.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 774998515600 + 729486081 = 880340^2 + 27009^2 .

It is a cyclic number.

It is not a de Polignac number, because 775728001681 - 2⁵ = 775728001649 is a prime.

It is a super-3 number, since 3×775728001681³ (a number of 37 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not a weakly prime, because it can be changed into another prime (775728001687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 387864000840 + 387864000841.

It is an arithmetic number, because the mean of its divisors is an integer number (387864000841).

Almost surely, 2^775728001681 is an apocalyptic number.

It is an amenable number.

775728001681 is a deficient number, since it is larger than the sum of its proper divisors (1).

775728001681 is an equidigital number, since it uses as much as digits as its factorization.

775728001681 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1317120, while the sum is 52.

The spelling of 775728001681 in words is "seven hundred seventy-five billion, seven hundred twenty-eight million, one thousand, six hundred eighty-one".