684746481581 has 2 divisors, whose sum is σ = 684746481582. Its totient is φ = 684746481580.

The previous prime is 684746481569. The next prime is 684746481613. The reversal of 684746481581 is 185184647486.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 504193724356 + 180552757225 = 710066^2 + 424915^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-684746481581 is a prime.

It is a super-2 number, since 2×684746481581² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (684746481521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342373240790 + 342373240791.

It is an arithmetic number, because the mean of its divisors is an integer number (342373240791).

Almost surely, 2^684746481581 is an apocalyptic number.

It is an amenable number.

684746481581 is a deficient number, since it is larger than the sum of its proper divisors (1).

684746481581 is an equidigital number, since it uses as much as digits as its factorization.

684746481581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 41287680, while the sum is 62.

The spelling of 684746481581 in words is "six hundred eighty-four billion, seven hundred forty-six million, four hundred eighty-one thousand, five hundred eighty-one".