777777641 has 2 divisors, whose sum is σ = 777777642. Its totient is φ = 777777640.

The previous prime is 777777577. The next prime is 777777643. The reversal of 777777641 is 146777777.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 576960400 + 200817241 = 24020^2 + 14171^2 .

It is a cyclic number.

It is not a de Polignac number, because 777777641 - 2⁶ = 777777577 is a prime.

Together with 777777643, it forms a pair of twin primes.

It is a Chen prime.

It is a nialpdrome in base 10.

It is not a weakly prime, because it can be changed into another prime (777777643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 388888820 + 388888821.

It is an arithmetic number, because the mean of its divisors is an integer number (388888821).

Almost surely, 2^777777641 is an apocalyptic number.

It is an amenable number.

777777641 is a deficient number, since it is larger than the sum of its proper divisors (1).

777777641 is an equidigital number, since it uses as much as digits as its factorization.

777777641 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2823576, while the sum is 53.

The square root of 777777641 is about 27888.6650989250. The cubic root of 777777641 is about 919.6413382185.

The spelling of 777777641 in words is "seven hundred seventy-seven million, seven hundred seventy-seven thousand, six hundred forty-one".