809857001 has 2 divisors, whose sum is σ = 809857002. Its totient is φ = 809857000.

The previous prime is 809856919. The next prime is 809857031. The reversal of 809857001 is 100758908.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 742617001 + 67240000 = 27251^2 + 8200^2 .

It is a cyclic number.

It is not a de Polignac number, because 809857001 - 2¹⁸ = 809594857 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (809857031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 404928500 + 404928501.

It is an arithmetic number, because the mean of its divisors is an integer number (404928501).

Almost surely, 2^809857001 is an apocalyptic number.

It is an amenable number.

809857001 is a deficient number, since it is larger than the sum of its proper divisors (1).

809857001 is an equidigital number, since it uses as much as digits as its factorization.

809857001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20160, while the sum is 38.

The square root of 809857001 is about 28457.9865942761. The cubic root of 809857001 is about 932.1148928613.

The spelling of 809857001 in words is "eight hundred nine million, eight hundred fifty-seven thousand, one".