811638761 has 2 divisors, whose sum is σ = 811638762. Its totient is φ = 811638760.

The previous prime is 811638739. The next prime is 811638787. The reversal of 811638761 is 167836118.

811638761 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 644195161 + 167443600 = 25381^2 + 12940^2 .

It is a cyclic number.

It is not a de Polignac number, because 811638761 - 2¹⁰ = 811637737 is a prime.

It is not a weakly prime, because it can be changed into another prime (811638721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 405819380 + 405819381.

It is an arithmetic number, because the mean of its divisors is an integer number (405819381).

Almost surely, 2^811638761 is an apocalyptic number.

It is an amenable number.

811638761 is a deficient number, since it is larger than the sum of its proper divisors (1).

811638761 is an equidigital number, since it uses as much as digits as its factorization.

811638761 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 48384, while the sum is 41.

The square root of 811638761 is about 28489.2744905868. The cubic root of 811638761 is about 932.7979717017.

The spelling of 811638761 in words is "eight hundred eleven million, six hundred thirty-eight thousand, seven hundred sixty-one".