685780247 has 2 divisors, whose sum is σ = 685780248. Its totient is φ = 685780246.

The previous prime is 685780217. The next prime is 685780253. The reversal of 685780247 is 742087586.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 685780247 - 2¹² = 685776151 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (685780217) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342890123 + 342890124.

It is an arithmetic number, because the mean of its divisors is an integer number (342890124).

Almost surely, 2^685780247 is an apocalyptic number.

685780247 is a deficient number, since it is larger than the sum of its proper divisors (1).

685780247 is an equidigital number, since it uses as much as digits as its factorization.

685780247 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 752640, while the sum is 47.

The square root of 685780247 is about 26187.4062671354. The cubic root of 685780247 is about 881.8505509128.

The spelling of 685780247 in words is "six hundred eighty-five million, seven hundred eighty thousand, two hundred forty-seven".