684866959668461 has 2 divisors, whose sum is σ = 684866959668462. Its totient is φ = 684866959668460.

The previous prime is 684866959668439. The next prime is 684866959668487. The reversal of 684866959668461 is 164866959668486.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 554279911922500 + 130587047745961 = 23543150^2 + 11427469^2 .

It is a cyclic number.

It is not a de Polignac number, because 684866959668461 - 2¹⁸ = 684866959406317 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (684866959668761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342433479834230 + 342433479834231.

It is an arithmetic number, because the mean of its divisors is an integer number (342433479834231).

Almost surely, 2^{684866959668461} is an apocalyptic number.

It is an amenable number.

684866959668461 is a deficient number, since it is larger than the sum of its proper divisors (1).

684866959668461 is an equidigital number, since it uses as much as digits as its factorization.

684866959668461 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 154793410560, while the sum is 92.

The spelling of 684866959668461 in words is "six hundred eighty-four trillion, eight hundred sixty-six billion, nine hundred fifty-nine million, six hundred sixty-eight thousand, four hundred sixty-one".