685111820801 has 2 divisors, whose sum is σ = 685111820802. Its totient is φ = 685111820800.

The previous prime is 685111820759. The next prime is 685111820839. The reversal of 685111820801 is 108028111586.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 684152308225 + 959512576 = 827135^2 + 30976^2 .

It is a cyclic number.

It is not a de Polignac number, because 685111820801 - 2³⁸ = 410233913857 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (685111823801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342555910400 + 342555910401.

It is an arithmetic number, because the mean of its divisors is an integer number (342555910401).

Almost surely, 2^685111820801 is an apocalyptic number.

It is an amenable number.

685111820801 is a deficient number, since it is larger than the sum of its proper divisors (1).

685111820801 is an equidigital number, since it uses as much as digits as its factorization.

685111820801 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 30720, while the sum is 41.

The spelling of 685111820801 in words is "six hundred eighty-five billion, one hundred eleven million, eight hundred twenty thousand, eight hundred one".