811909873 has 2 divisors, whose sum is σ = 811909874. Its totient is φ = 811909872.

The previous prime is 811909837. The next prime is 811909883. The reversal of 811909873 is 378909118.

Together with previous prime (811909837) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 421768369 + 390141504 = 20537^2 + 19752^2 .

It is a cyclic number.

It is not a de Polignac number, because 811909873 - 2¹⁷ = 811778801 is a prime.

It is a super-2 number, since 2×811909873² = 1318395283749752258, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (811909883) 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, 405954936 + 405954937.

It is an arithmetic number, because the mean of its divisors is an integer number (405954937).

Almost surely, 2^811909873 is an apocalyptic number.

It is an amenable number.

811909873 is a deficient number, since it is larger than the sum of its proper divisors (1).

811909873 is an equidigital number, since it uses as much as digits as its factorization.

811909873 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 108864, while the sum is 46.

The square root of 811909873 is about 28494.0322348382. The cubic root of 811909873 is about 932.9018210918.

The spelling of 811909873 in words is "eight hundred eleven million, nine hundred nine thousand, eight hundred seventy-three".