776561 has 2 divisors, whose sum is σ = 776562. Its totient is φ = 776560.

The previous prime is 776557. The next prime is 776563. The reversal of 776561 is 165677.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 776161 + 400 = 881^2 + 20^2 .

It is a cyclic number.

It is not a de Polignac number, because 776561 - 2² = 776557 is a prime.

Together with 776563, it forms a pair of twin primes.

It is a Chen prime.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 776561.

It is not a weakly prime, because it can be changed into another prime (776563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 388280 + 388281.

It is an arithmetic number, because the mean of its divisors is an integer number (388281).

2⁷⁷⁶⁵⁶¹ is an apocalyptic number.

It is an amenable number.

776561 is a deficient number, since it is larger than the sum of its proper divisors (1).

776561 is an equidigital number, since it uses as much as digits as its factorization.

776561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8820, while the sum is 32.

The square root of 776561 is about 881.2269855151. The cubic root of 776561 is about 91.9161570735.

The spelling of 776561 in words is "seven hundred seventy-six thousand, five hundred sixty-one".