81193275885393 has 12 divisors (see below), whose sum is σ = 134033344318848. Its totient is φ = 46396157648760.

The previous prime is 81193275885373. The next prime is 81193275885401. The reversal of 81193275885393 is 39358857239118.

81193275885393 is a `hidden beast` number, since 8 + 1 + 1 + 9 + 3 + 2 + 7 + 5 + 88 + 539 + 3 = 666.

It is not a de Polignac number, because 81193275885393 - 2²¹ = 81193273788241 is a prime.

It is a Smith number, since the sum of its digits (72) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (81193275885313) 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, 644391078393 + ... + 644391078518.

It is an arithmetic number, because the mean of its divisors is an integer number (11169445359904).

Almost surely, 2^{81193275885393} is an apocalyptic number.

It is an amenable number.

81193275885393 is a deficient number, since it is larger than the sum of its proper divisors (52840068433455).

81193275885393 is a wasteful number, since it uses less digits than its factorization.

81193275885393 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1288782156924 (or 1288782156921 counting only the distinct ones).

The product of its digits is 391910400, while the sum is 72.

The spelling of 81193275885393 in words is "eighty-one trillion, one hundred ninety-three billion, two hundred seventy-five million, eight hundred eighty-five thousand, three hundred ninety-three".