81135862794 has 24 divisors (see below), whose sum is σ = 200907851040. Its totient is φ = 23181675048.

The previous prime is 81135862789. The next prime is 81135862799. The reversal of 81135862794 is 49726853118.

81135862794 is a `hidden beast` number, since 8 + 1 + 1 + 3 + 5 + 8 + 627 + 9 + 4 = 666.

It is an interprime number because it is at equal distance from previous prime (81135862789) and next prime (81135862799).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 81135862794.

It is not an unprimeable number, because it can be changed into a prime (81135862799) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 321967584 + ... + 321967835.

It is an arithmetic number, because the mean of its divisors is an integer number (8371160460).

Almost surely, 2^81135862794 is an apocalyptic number.

81135862794 is an abundant number, since it is smaller than the sum of its proper divisors (119771988246).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81135862794 is a wasteful number, since it uses less digits than its factorization.

81135862794 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 643935434 (or 643935431 counting only the distinct ones).

The product of its digits is 2903040, while the sum is 54.

The spelling of 81135862794 in words is "eighty-one billion, one hundred thirty-five million, eight hundred sixty-two thousand, seven hundred ninety-four".