684977 has 2 divisors, whose sum is σ = 684978. Its totient is φ = 684976.

The previous prime is 684973. The next prime is 684989. The reversal of 684977 is 779486.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 524176 + 160801 = 724^2 + 401^2 .

It is a cyclic number.

It is not a de Polignac number, because 684977 - 2² = 684973 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (684973) 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, 342488 + 342489.

It is an arithmetic number, because the mean of its divisors is an integer number (342489).

2⁶⁸⁴⁹⁷⁷ is an apocalyptic number.

It is an amenable number.

684977 is a deficient number, since it is larger than the sum of its proper divisors (1).

684977 is an equidigital number, since it uses as much as digits as its factorization.

684977 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 84672, while the sum is 41.

The square root of 684977 is about 827.6333729376. The cubic root of 684977 is about 88.1506115723.

It can be divided in two parts, 684 and 977, that added together give a palindrome (1661).

The spelling of 684977 in words is "six hundred eighty-four thousand, nine hundred seventy-seven".