811205051 has 2 divisors, whose sum is σ = 811205052. Its totient is φ = 811205050.

The previous prime is 811205041. The next prime is 811205123. The reversal of 811205051 is 150502118.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 811205051 - 2¹⁰ = 811204027 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (811205011) 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, 405602525 + 405602526.

It is an arithmetic number, because the mean of its divisors is an integer number (405602526).

Almost surely, 2^811205051 is an apocalyptic number.

811205051 is a deficient number, since it is larger than the sum of its proper divisors (1).

811205051 is an equidigital number, since it uses as much as digits as its factorization.

811205051 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 400, while the sum is 23.

The square root of 811205051 is about 28481.6616614972. The cubic root of 811205051 is about 932.6317910843.

Adding to 811205051 its reverse (150502118), we get a palindrome (961707169).

The spelling of 811205051 in words is "eight hundred eleven million, two hundred five thousand, fifty-one".