809733241721 has 2 divisors, whose sum is σ = 809733241722. Its totient is φ = 809733241720.

The previous prime is 809733241661. The next prime is 809733241777. The reversal of 809733241721 is 127142337908.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 635226534121 + 174506707600 = 797011^2 + 417740^2 .

It is a cyclic number.

It is not a de Polignac number, because 809733241721 - 2¹⁸ = 809732979577 is a prime.

It is not a weakly prime, because it can be changed into another prime (809733241781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 404866620860 + 404866620861.

It is an arithmetic number, because the mean of its divisors is an integer number (404866620861).

Almost surely, 2^809733241721 is an apocalyptic number.

It is an amenable number.

809733241721 is a deficient number, since it is larger than the sum of its proper divisors (1).

809733241721 is an equidigital number, since it uses as much as digits as its factorization.

809733241721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 508032, while the sum is 47.

The spelling of 809733241721 in words is "eight hundred nine billion, seven hundred thirty-three million, two hundred forty-one thousand, seven hundred twenty-one".