81811093777 has 16 divisors (see below), whose sum is σ = 99009630720. Its totient is φ = 65991310848.

The previous prime is 81811093759. The next prime is 81811093783. The reversal of 81811093777 is 77739011818.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 81811093777 - 2¹¹ = 81811091729 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81811096777) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1156728 + ... + 1225414.

It is an arithmetic number, because the mean of its divisors is an integer number (6188101920).

Almost surely, 2^81811093777 is an apocalyptic number.

It is an amenable number.

81811093777 is a deficient number, since it is larger than the sum of its proper divisors (17198536943).

81811093777 is a wasteful number, since it uses less digits than its factorization.

81811093777 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78720.

The product of its (nonzero) digits is 592704, while the sum is 52.

The spelling of 81811093777 in words is "eighty-one billion, eight hundred eleven million, ninety-three thousand, seven hundred seventy-seven".