685657601 has 2 divisors, whose sum is σ = 685657602. Its totient is φ = 685657600.

The previous prime is 685657591. The next prime is 685657613. The reversal of 685657601 is 106756586.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 599074576 + 86583025 = 24476^2 + 9305^2 .

It is a cyclic number.

It is not a de Polignac number, because 685657601 - 2¹⁰ = 685656577 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (685657631) 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, 342828800 + 342828801.

It is an arithmetic number, because the mean of its divisors is an integer number (342828801).

Almost surely, 2^685657601 is an apocalyptic number.

It is an amenable number.

685657601 is a deficient number, since it is larger than the sum of its proper divisors (1).

685657601 is an equidigital number, since it uses as much as digits as its factorization.

685657601 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 302400, while the sum is 44.

The square root of 685657601 is about 26185.0644643087. The cubic root of 685657601 is about 881.7979772731.

The spelling of 685657601 in words is "six hundred eighty-five million, six hundred fifty-seven thousand, six hundred one".