811777381 has 2 divisors, whose sum is σ = 811777382. Its totient is φ = 811777380.

The previous prime is 811777363. The next prime is 811777399. The reversal of 811777381 is 183777118.

811777381 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a balanced prime because it is at equal distance from previous prime (811777363) and next prime (811777399).

It can be written as a sum of positive squares in only one way, i.e., 492440481 + 319336900 = 22191^2 + 17870^2 .

It is a cyclic number.

It is not a de Polignac number, because 811777381 - 2¹¹ = 811775333 is a prime.

It is a super-2 number, since 2×811777381² = 1317965032606438322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (811777321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 405888690 + 405888691.

It is an arithmetic number, because the mean of its divisors is an integer number (405888691).

Almost surely, 2^811777381 is an apocalyptic number.

It is an amenable number.

811777381 is a deficient number, since it is larger than the sum of its proper divisors (1).

811777381 is an equidigital number, since it uses as much as digits as its factorization.

811777381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 65856, while the sum is 43.

The square root of 811777381 is about 28491.7072321053. The cubic root of 811777381 is about 932.8510729500.

The spelling of 811777381 in words is "eight hundred eleven million, seven hundred seventy-seven thousand, three hundred eighty-one".