811934509 has 2 divisors, whose sum is σ = 811934510. Its totient is φ = 811934508.

The previous prime is 811934503. The next prime is 811934537. The reversal of 811934509 is 905439118.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 696801609 + 115132900 = 26397^2 + 10730^2 .

It is a cyclic number.

It is not a de Polignac number, because 811934509 - 2⁷ = 811934381 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (811934503) 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, 405967254 + 405967255.

It is an arithmetic number, because the mean of its divisors is an integer number (405967255).

Almost surely, 2^811934509 is an apocalyptic number.

It is an amenable number.

811934509 is a deficient number, since it is larger than the sum of its proper divisors (1).

811934509 is an equidigital number, since it uses as much as digits as its factorization.

811934509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 38880, while the sum is 40.

The square root of 811934509 is about 28494.4645326070. The cubic root of 811934509 is about 932.9112567601.

The spelling of 811934509 in words is "eight hundred eleven million, nine hundred thirty-four thousand, five hundred nine".