810729961 has 2 divisors, whose sum is σ = 810729962. Its totient is φ = 810729960.

The previous prime is 810729947. The next prime is 810730001. The reversal of 810729961 is 169927018.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 561690000 + 249039961 = 23700^2 + 15781^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-810729961 is a prime.

It is not a weakly prime, because it can be changed into another prime (810729911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 405364980 + 405364981.

It is an arithmetic number, because the mean of its divisors is an integer number (405364981).

Almost surely, 2^810729961 is an apocalyptic number.

It is an amenable number.

810729961 is a deficient number, since it is larger than the sum of its proper divisors (1).

810729961 is an equidigital number, since it uses as much as digits as its factorization.

810729961 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 54432, while the sum is 43.

The square root of 810729961 is about 28473.3201611614. The cubic root of 810729961 is about 932.4496872854.

The spelling of 810729961 in words is "eight hundred ten million, seven hundred twenty-nine thousand, nine hundred sixty-one".