800865001 has 2 divisors, whose sum is σ = 800865002. Its totient is φ = 800865000.

The previous prime is 800864993. The next prime is 800865047. The reversal of 800865001 is 100568008.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 451137600 + 349727401 = 21240^2 + 18701^2 .

It is a cyclic number.

It is not a de Polignac number, because 800865001 - 2³ = 800864993 is a prime.

It is not a weakly prime, because it can be changed into another prime (800865061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 400432500 + 400432501.

It is an arithmetic number, because the mean of its divisors is an integer number (400432501).

Almost surely, 2^800865001 is an apocalyptic number.

It is an amenable number.

800865001 is a deficient number, since it is larger than the sum of its proper divisors (1).

800865001 is an equidigital number, since it uses as much as digits as its factorization.

800865001 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1920, while the sum is 28.

The square root of 800865001 is about 28299.5583181081. The cubic root of 800865001 is about 928.6522277879.

The spelling of 800865001 in words is "eight hundred million, eight hundred sixty-five thousand, one".