685266401 has 2 divisors, whose sum is σ = 685266402. Its totient is φ = 685266400.

The previous prime is 685266353. The next prime is 685266409. The reversal of 685266401 is 104662586.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 489294400 + 195972001 = 22120^2 + 13999^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-685266401 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 (685266409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342633200 + 342633201.

It is an arithmetic number, because the mean of its divisors is an integer number (342633201).

Almost surely, 2^685266401 is an apocalyptic number.

It is an amenable number.

685266401 is a deficient number, since it is larger than the sum of its proper divisors (1).

685266401 is an equidigital number, since it uses as much as digits as its factorization.

685266401 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 69120, while the sum is 38.

The square root of 685266401 is about 26177.5934913811. The cubic root of 685266401 is about 881.6302429238.

The spelling of 685266401 in words is "six hundred eighty-five million, two hundred sixty-six thousand, four hundred one".