678761 has 2 divisors, whose sum is σ = 678762. Its totient is φ = 678760.

The previous prime is 678757. The next prime is 678763. The reversal of 678761 is 167876.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 534361 + 144400 = 731^2 + 380^2 .

It is a cyclic number.

It is not a de Polignac number, because 678761 - 2² = 678757 is a prime.

Together with 678763, it forms a pair of twin primes.

It is a Chen prime.

It is an alternating number because its digits alternate between even and odd.

It is not a weakly prime, because it can be changed into another prime (678763) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 339380 + 339381.

It is an arithmetic number, because the mean of its divisors is an integer number (339381).

2⁶⁷⁸⁷⁶¹ is an apocalyptic number.

It is an amenable number.

678761 is a deficient number, since it is larger than the sum of its proper divisors (1).

678761 is an equidigital number, since it uses as much as digits as its factorization.

678761 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 14112, while the sum is 35.

The square root of 678761 is about 823.8695285056. The cubic root of 678761 is about 87.8831524238.

The spelling of 678761 in words is "six hundred seventy-eight thousand, seven hundred sixty-one".